Somewhere right now, a car shopper is squinting at a brochure that says 150 kW and wondering how many horsepower that is. An HVAC technician is telling a homeowner she needs a "3-ton" air conditioner, and she is politely nodding while having no idea what a ton of cold air even means. An engineer in a data center is converting megawatts to BTU per hour to size a cooling loop. All three of them need the same thing: a fast, accurate power unit converter.
That is exactly what the free tool at the top of this page does. It converts between 40 power units — watts, kilowatts, megawatts, four different kinds of horsepower, BTU/h, tons of refrigeration, kilocalories per hour, kVA and more — instantly, in six languages, with no ads, no sign-up and no tracking. This guide is its companion. In the next few thousand words we will explain what power actually is, where every one of those 40 units comes from, the exact conversion factors and formulas the converter uses under the hood, and how to apply them to real situations in 2026: electric cars, solar panels, heat pumps, generators, even the wattage of your own body.
Bookmark this page. Between the live power conversion calculator above and the reference tables below, it is the only power conversion resource you should ever need.
Power Unit Converter Embed Code for Your Website:
Power is the heartbeat of our modern world – it's what lights up our cities, propels our vehicles, powers our devices, and fuels our industries. Yet, power speaks in many voices. A watt whispers the story of a light bulb, a horsepower roars with the strength of an engine, and a kilowatt captures the energy of a household's daily rhythm. This tool was created to help everyone understand the language of power, no matter which unit they speak.
You can copy this code and embed it on your website, offering your visitors a thoughtful, practical companion that illuminates how they think about power and energy. Whether they're comparing the output of different appliances, calculating energy costs for their home, studying thermodynamics in class, or simply curious about how horsepower compares to watts, this Power Unit Converter turns complex comparisons into simple, intuitive understanding.
The Power Unit Converter is an elegantly simple, interactive tool that allows your website visitors to instantly convert between watts, kilowatts, megawatts, horsepower, BTU per hour, and more. Simply enter a value in any unit, and watch as all other units update in perfect harmony – transforming what could be a confusing technical exercise into a moment of effortless clarity.
This tool is essential for engineering and technology blogs, energy and sustainability websites, automotive and mechanics platforms, home improvement and appliance review sites, or any space where power and performance matter. It's more than a converter – it's a bridge that connects people across different measurement traditions and ways of understanding the energy that drives our world.
The code is available in six global languages to welcome visitors from every corner of the earth: English - Spanish - French - Arabic - Chinese - Hindi.
You can easily switch the converter language by changing the parameter in the URL: ?lang=en
Available languages: en - es - fr - ar - zh - hi
1- Isolated iFrame Code (Ideal for Articles and Pages):
If you're writing about engineering marvels, sustainable energy solutions, automotive performance, or everyday technology, this method allows you to embed the tool directly within your content. The isolated iframe ensures a clean, focused experience, so your readers can experiment with power conversions alongside your insights – connecting the numbers to the real-world technologies that make power such a fascinating and essential subject.
<iframe id="tq_power_converter" src="https://tools.tooliqo.co/power-converter/?lang=en" title="Tooliqo" loading="lazy" scrolling="no" style="width:100%;max-width:100%;height:649px;border:0;overflow:hidden;display:block;margin:0 auto;"></iframe>
<script>(function(){var i="tq_power_converter",b="https://tools.tooliqo.co/power-converter/",dl="en";function L(){try{var h=(document.documentElement.getAttribute("lang")||"").toLowerCase();var ok=["ar","en","fr","es","zh","hi"];for(var k=0;k<ok.length;k++){if(h.indexOf(ok[k])===0)return ok[k];}}catch(e){}return dl;}function R(){var f=document.getElementById(i);if(!f)return;var lg=L();if(lg){var want=b+"?lang="+lg;if((f.getAttribute("src")||"").indexOf("lang="+lg)===-1)f.setAttribute("src",want);}window.addEventListener("message",function(e){var d=e.data;if(!d||typeof d.tqHeight!=="number"||d.tqHeight<50)return;try{if(f.contentWindow&&e.source&&e.source!==f.contentWindow)return;}catch(x){}f.style.height=(d.tqHeight+20)+"px";},false);}if(document.readyState==="loading"){document.addEventListener("DOMContentLoaded",R);}else{R();}})();</script>
2- Flexible Script (Suitable for Sidebars and Templates):
This method is perfect for sidebars, footers, or widget areas where you want the tool to be always within reach. The converter loads smoothly and gracefully, becoming a trusted companion that helps your visitors navigate the world of power – whether they're comparing appliance efficiency, calculating energy requirements for a project, or simply exploring the fascinating relationships between different units of power measurement.
Just add these lines to your website's code, and the Power Unit Converter will appear instantly, ready to help. It's fully responsive by design, offering a flawless experience on desktops, tablets, and mobile phones.
<div class="tooliqo-tool" data-tool="power-converter" data-lang="en"></div> <script src="https://tools.tooliqo.co/embed.js" async></script>
Note: The Power Unit Converter works in real-time, instantly updating all units as your visitors type or adjust values. No page reloads needed – just a smooth, intuitive experience that makes power feel less like abstract engineering and more like something we can all understand and appreciate. Because when we understand power better, we connect more deeply with the technologies that light up our lives and drive our world forward.
What Does "Power" Actually Mean? Watts, Energy and Time
Power is one of those words we use loosely in everyday speech — powerful engines, powerful people, power naps — but in physics and engineering it has a razor-sharp definition: power is the rate at which energy is transferred or converted. Not how much energy, but how fast.
The formula could not be simpler:
Power = Energy ÷ Time
The SI unit of power is the watt (W), defined as one joule per second. If a machine converts one joule of energy every second, it is running at exactly one watt. Deliver those joules twice as fast and you have two watts. Same energy, different power.
A road-trip analogy makes this stick. Energy is like distance — the total ground you cover. Power is like speed — how quickly you cover it. Two cars can both drive 300 kilometres (same energy), but the one that does it in three hours is operating at a higher "power" than the one that takes six. This is also the cleanest way to untangle the most common confusion in the entire field: kW versus kWh.
A kilowatt (kW) is power — a rate. A kilowatt-hour (kWh) is energy — an amount. Your 2 kW space heater draws energy at a rate of 2 kW; run it for three hours and it has consumed 2 × 3 = 6 kWh, which is what your electricity company actually bills you for. When someone says "my solar system produced 30 kilowatts yesterday," they almost always mean 30 kilowatt-hours. The converter on this page deals purely with power. If you need to convert energy units like joules, kWh and calories, that is a separate job (we built a dedicated energy converter for it on Tooliqo as well).
One more foundation before we climb the unit ladder: because power is universal — mechanical, electrical, thermal, it does not matter — every power unit ever invented can be expressed in watts. A horsepower is a certain number of watts. A BTU per hour is a certain number of watts. A ton of refrigeration is a certain number of watts. That single fact is what makes a universal power unit converter possible, and we will use it as our anchor throughout this article.
The Watt Family: From Picowatts to Petawatts
The watt is named after James Watt, the Scottish engineer whose improvements to the steam engine helped ignite the Industrial Revolution. The unit was adopted internationally in 1889 and folded into the SI system in 1960. Because a single watt is quite small — a modern LED bulb sips 8 to 10 of them — the metric system stacks prefixes on top, each step multiplying or dividing by 1,000.
Here is the full ladder our converter covers, with a real-world example at every rung so the numbers mean something:
| Unit | Symbol | In watts | Real-world example |
|---|---|---|---|
| Picowatt | pW | 10−12 W | Radio signals captured by radio telescopes from deep space |
| Nanowatt | nW | 10−9 W | Ultra-low-power biosensors and medical implants |
| Microwatt | µW | 10−6 W | A passive RFID tag harvesting energy from a reader |
| Milliwatt | mW | 0.001 W | A laser pointer (1–5 mW); Bluetooth earbuds streaming audio |
| Watt | W | 1 W | An LED night light; a phone trickle-charging |
| Kilowatt | kW | 1,000 W | An electric kettle (2–3 kW); a home EV charger (7 kW) |
| Megawatt | MW | 106 W | A modern onshore wind turbine (3–6 MW) |
| Gigawatt | GW | 109 W | A large nuclear reactor unit (~1 GW) |
| Terawatt | TW | 1012 W | All of humanity's average energy use (~19–20 TW, continuous) |
| Petawatt | PW | 1015 W | Sunlight striking the entire Earth (~174 PW) |
A few of these numbers deserve a moment of awe. The sunlight figure means our planet receives roughly 174 petawatts continuously — about 9,000 times more power than human civilisation consumes. A single lightning bolt briefly peaks around a terawatt, but only for microseconds, which is why it carries surprisingly little total energy despite the drama. And the Sun itself radiates about 3.8 × 1026 W, a number so large that even petawatts stop being useful — which is exactly why our converter switches to scientific notation automatically when values get extreme.
Engineers move up and down this ladder constantly. Nobody says a wind turbine produces "five million watts"; they say 5 MW. Nobody rates a hearing aid in kilowatts. Choosing the right rung keeps numbers human-sized, and converting between rungs is just a matter of shifting the decimal point three places per step — something the tool above does for you without a single mental arithmetic error at 2 a.m.
Horsepower Explained: Why There Are Five Different Horsepowers
Here is the origin story, because it is genuinely one of the best marketing moves in engineering history. In the late 1700s, James Watt was trying to sell his improved steam engines to breweries and mines that were still using actual horses to turn mill wheels and haul water. Buyers had one question: how many of my horses does your machine replace?
So Watt measured. He watched draft horses walking in circles turning mill mechanisms, did the maths on load, distance and time, and settled on a figure: a healthy working horse could sustain about 33,000 foot-pounds of work per minute. Divide by 60 and you get the definition that survives to this day:
One mechanical horsepower is the power required to lift 550 pounds by one foot in one second — equal to exactly 550 ft·lbf/s, or 745.6998716 watts.
It was deliberately a bit generous — a real horse cannot hold that output all day — which meant Watt's engines always over-delivered on their promise. Customers loved it. The unit stuck. And then, because history is messy, the rest of the world invented four more horsepowers:
| Horsepower type | Symbol | Exact watts | ≈ kW | Where you meet it |
|---|---|---|---|---|
| Mechanical (imperial) | hp | 745.699872 | 0.7457 | US & UK car specs, mowers, outboard motors |
| Metric horsepower | PS (also cv, ch) | 735.49875 | 0.7355 | European & Japanese car brochures |
| Electrical horsepower | hp(E) | 746 | 0.746 | Electric motor nameplates |
| Boiler horsepower | hp(S) | 9,809.5 | 9.8095 | Industrial steam boiler ratings |
| Water (hydraulic) horsepower | hp(water) | 746.043 | 0.746 | Pump and hydraulic system sizing |
The one that trips people up daily is metric horsepower (PS), from the German Pferdestärke. It was defined as the power needed to lift 75 kilograms by one metre in one second, which works out to 735.49875 W — about 1.4% smaller than the imperial horsepower. Small difference, big consequences: a car advertised as "300 PS" in Germany is only about 296 hp in American terms. Marketers know which number looks bigger, and they use it.
Then there is boiler horsepower, the eccentric of the family. It is not even in the same weight class — one boiler horsepower equals roughly 9.81 kW, or about 13.15 mechanical horsepower, because it was defined around evaporating 34.5 pounds of water per hour into steam. If you ever see a boiler rated "100 hp" and wonder how a water heater outmuscles a sports car, that is why: different horsepower entirely.
The electric-vehicle era is quietly retiring the horse. EU regulations require motor output in kilowatts, so a Volkswagen ID.-series brochure will lead with something like "150 kW", leaving you to translate: 150 kW = 201.15 hp = 203.94 PS. Type it into the converter above and you will get all three in one keystroke — including the tidy formula line "1 kW = 1.3410220896 hp" shown right under the result.
BTU/h, Tons of Refrigeration and the Language of Heating & Cooling
Walk into the world of air conditioners, furnaces and heat pumps and the watts suddenly vanish. Here everything speaks BTU per hour and tons, and both units have wonderful backstories.
A British Thermal Unit (BTU) is the energy needed to raise one pound of water by one degree Fahrenheit — a unit of energy, like a joule. Add "per hour" and it becomes a unit of power: 1 BTU/h = 0.29307107 W. This distinction matters enormously. When a shop sells you a "12,000 BTU air conditioner," they technically mean 12,000 BTU per hour; the "/h" gets dropped in casual speech, and more than one buyer has been confused into comparing energy with power.
The ton of refrigeration (TR) is even better. Before mechanical cooling, America ran on harvested ice. Cooling capacity was literally measured in blocks of ice, so when refrigeration machines arrived in the late 1800s, engineers defined their output in the same currency: one ton of refrigeration is the cooling delivered by melting one short ton (2,000 lb) of ice over 24 hours. Melting ice absorbs 144 BTU per pound, so 2,000 lb × 144 BTU = 288,000 BTU per day, and 288,000 ÷ 24 gives the definition every HVAC tech knows by heart:
1 ton of refrigeration = 12,000 BTU/h = 3,516.85 W ≈ 3.517 kW
So when the technician says your house needs "3 tons," he means an air conditioner that removes heat at 36,000 BTU/h, or about 10.55 kW of thermal power. No actual ice is involved, though the ghost of the ice trade lives on in every spec sheet.
Two more heating units round out the family. MBH means one thousand BTU per hour (M is the Roman numeral for 1,000 here) and appears on commercial furnaces and boilers. MMBtu/h — one million BTU per hour, equal to 293.07 kW — is the workhorse of industrial energy contracts, gas burners and power-plant engineering. Meanwhile, much of Europe, Latin America and the Middle East rates radiators, water heaters and gas appliances in kilocalories per hour (kcal/h), where 1 kcal/h = 1.163 W and, conveniently, 1 kW = 859.845 kcal/h.
Because air-conditioner sizing is one of the most common reasons people reach for a power converter, here is the cheat sheet, generated with the exact factors from our tool:
| Cooling capacity (BTU/h) | Kilowatts (kW) | Tons of refrigeration |
|---|---|---|
| 9,000 | 2.64 | 0.75 |
| 12,000 | 3.52 | 1 |
| 18,000 | 5.28 | 1.5 |
| 24,000 | 7.03 | 2 |
| 36,000 | 10.55 | 3 |
| 48,000 | 14.07 | 4 |
| 60,000 | 17.58 | 5 |
A note for the heat-pump generation: heat pumps are usually specified by their thermal output in kW (Europe) or BTU/h (North America), while their electrical input is a much smaller number. A unit with a COP of 3.5 delivers 3.5 kW of heat for every 1 kW of electricity it draws. Both figures are power; the converter handles either one, and knowing the difference is how you read a heat-pump datasheet like a professional.
kW vs kVA: Real Power, Apparent Power and the Power Factor
If you have ever shopped for a generator, a UPS or a transformer, you have hit the kVA wall. The unit looks like it should be a kilowatt's twin — and sometimes it is — but treating them as identical is one of the most expensive mistakes in electrical sizing.
In AC electrical systems, the volt-ampere (VA) measures apparent power: voltage times current, the total electrical traffic flowing through the wires. The watt measures real power: the portion of that traffic actually converted into useful work or heat. The ratio between them is the power factor (PF):
kW = kVA × power factor
The classic analogy is a glass of beer. The liquid is real power (kW) — the part you actually drink. The foam is reactive power, sloshing back and forth doing nothing useful. The full glass, liquid plus foam, is apparent power (kVA). A purely resistive load like an electric heater is all liquid: PF = 1.0, and kW equals kVA exactly. Induction motors, compressors and older lighting run at PF around 0.8 to 0.9. Modern electronics with power-factor correction get close to 0.95–0.99.
Generators, UPS systems and transformers are rated in kVA because their limits are set by current and voltage, not by what your particular load does with them. The industry-standard assumption is PF = 0.8, so a "10 kVA" generator is typically good for about 8 kW of real load. Undersize that and your "10 kVA" set stalls under an 9.5 kW workshop.
Our converter includes VA, kVA and MVA and treats them at unity power factor (1 VA = 1 W), which is the standard convention for unit conversion. For real-world sizing, do the conversion first, then multiply by your actual power factor — or divide, if you are going from kW to the kVA you need to buy. It is a one-line calculation that saves four-figure mistakes.
Joules per Second, Foot-Pounds and the Science-Lab Units
A cluster of units in the converter's "Mechanical & engineering" group deserves a quick tour, because they show up in textbooks, datasheets and machine shops far more than in daily life.
Joule per second (J/s) is simply the watt wearing its physics uniform — they are identical by definition, and the converter includes J/s, J/min, J/h, kJ/s, kJ/min and kJ/h because laboratory equipment and HVAC engineering (especially in metric countries) often quote heat rates in kilojoules per hour. Handy anchor: 1 kJ/h = 0.2778 W, and 1 kW = 3,600 kJ/h.
Newton-metre per second (N·m/s) is also exactly one watt, but its form reveals something useful: power equals torque times rotational speed. In SI terms, P (watts) = torque (N·m) × angular velocity (rad/s). In workshop terms, the imperial version produces one of the most beloved facts in automotive engineering: horsepower = torque (lb·ft) × RPM ÷ 5,252 — which is why, on every dyno chart ever printed, the horsepower and torque curves cross at exactly 5,252 RPM. If they cross anywhere else, someone fudged the graph.
The foot-pound-force per second (ft·lbf/s) family — per second, per minute, per hour — is the imperial ancestor of them all; remember that 550 ft·lbf/s is literally the definition of one horsepower. And the tiny erg per second (10−7 W) survives from the old CGS system mainly in astrophysics, where researchers still quote the luminosity of stars and quasars in ergs per second, partly out of tradition and partly because the numbers were already astronomical anyway.
How Power Conversion Works: One Formula for All 40 Units
Here is the engine room of the converter — and the method you can use with nothing but a pocket calculator.
Every power unit is defined as some fixed number of watts. That number is its conversion factor. To convert any value from unit A to unit B, you route it through watts as a hub:
Result = Value × (factor of A ÷ factor of B)
Three worked examples, using the exact factors from the tables below:
- 150 hp to kilowatts. Factor of hp is 745.699872; factor of kW is 1,000. Result = 150 × 745.699872 ÷ 1,000 = 111.855 kW. (This is why "1 hp ≈ 0.7457 kW" is the single most useful number in this article.)
- 24,000 BTU/h to kilowatts and tons. 24,000 × 0.29307107 ÷ 1,000 = 7.034 kW; and 24,000 ÷ 12,000 = 2 tons exactly. A "24,000 BTU" mini-split is a 2-ton, 7 kW cooling machine.
- A 500 kVA generator at 0.8 power factor, in horsepower. Real power = 500 × 0.8 = 400 kW. Then 400 × 1,000 ÷ 745.699872 = 536.41 hp. That is roughly the output of a large marine diesel — a good sanity check.
The converter above runs this exact hub-and-spoke calculation with double-precision arithmetic and displays up to 12 significant digits, then shows you the per-unit rate on its formula line (for example, "1 TR = 3.5168528421 kW") so you can verify or reuse the factor yourself. Nothing is hidden; the tables below are the tool's internal data, published in full.
Power Conversion Tables: Exact Factors for All 40 Units
These five tables list every unit the converter supports and its exact value in watts. They double as a permanent offline reference — screenshot them, print them, tape them inside a toolbox lid.
SI and metric watt units
| Unit | Symbol | Watts |
|---|---|---|
| Picowatt | pW | 10−12 |
| Nanowatt | nW | 10−9 |
| Microwatt | µW | 10−6 |
| Milliwatt | mW | 0.001 |
| Watt | W | 1 |
| Kilowatt | kW | 1,000 |
| Megawatt | MW | 1,000,000 |
| Gigawatt | GW | 109 |
| Terawatt | TW | 1012 |
| Petawatt | PW | 1015 |
Horsepower units
| Unit | Symbol | Watts |
|---|---|---|
| Horsepower (mechanical) | hp | 745.699872 |
| Horsepower (metric) | PS | 735.49875 |
| Horsepower (electric) | hp(E) | 746 |
| Horsepower (boiler) | hp(S) | 9,809.5 |
| Horsepower (water) | hp(water) | 746.043 |
Heat and refrigeration units
| Unit | Symbol | Watts |
|---|---|---|
| BTU per second | BTU/s | 1,055.05585 |
| BTU per minute | BTU/min | 17.5842642 |
| BTU per hour | BTU/h | 0.29307107 |
| MBH (1,000 BTU/h) | MBH | 293.07107 |
| MMBtu per hour | MMBtu/h | 293,071.07 |
| Ton of refrigeration | TR | 3,516.85284 |
| Calorie per second | cal/s | 4.1868 |
| Calorie per hour | cal/h | 0.001163 |
| Kilocalorie per second | kcal/s | 4,186.8 |
| Kilocalorie per minute | kcal/min | 69.78 |
| Kilocalorie per hour | kcal/h | 1.163 |
Mechanical and engineering units
| Unit | Symbol | Watts |
|---|---|---|
| Joule per second | J/s | 1 |
| Joule per minute | J/min | 0.0166667 |
| Joule per hour | J/h | 0.000277778 |
| Kilojoule per second | kJ/s | 1,000 |
| Kilojoule per minute | kJ/min | 16.6667 |
| Kilojoule per hour | kJ/h | 0.277778 |
| Newton-metre per second | N·m/s | 1 |
| Foot-pound per second | ft·lbf/s | 1.35581795 |
| Foot-pound per minute | ft·lbf/min | 0.0225969658 |
| Foot-pound per hour | ft·lbf/h | 0.000376616 |
| Erg per second | erg/s | 10−7 |
Electrical (apparent power) units
| Unit | Symbol | Watts (at PF = 1) |
|---|---|---|
| Volt-ampere | VA | 1 |
| Kilovolt-ampere | kVA | 1,000 |
| Megavolt-ampere | MVA | 1,000,000 |
As covered above, VA equals W only at a power factor of 1.0. For real AC loads, multiply the kVA figure by your power factor to get true kilowatts.
Quick Conversion Values: The Numbers You Will Use Most
The converter has a collapsible "Quick conversions" panel that instantly shows your value across the eight most-used power units. These two tables reproduce that panel for a value of 1 in each unit — the fastest way to eyeball any conversion without touching a keyboard.
Metric and mechanical equivalents
| Base value | Kilowatts (kW) | Horsepower (hp) | Metric HP (PS) |
|---|---|---|---|
| 1 W | 0.001 | 0.00134102 | 0.00135962 |
| 1 kW | 1 | 1.34102 | 1.35962 |
| 1 MW | 1,000 | 1,341.02 | 1,359.62 |
| 1 hp | 0.745700 | 1 | 1.01387 |
| 1 PS | 0.735499 | 0.986320 | 1 |
| 1 BTU/h | 0.000293071 | 0.000393015 | 0.000398466 |
| 1 TR | 3.51685 | 4.71618 | 4.78159 |
| 1 kcal/h | 0.001163 | 0.00155962 | 0.00158124 |
Heating and cooling equivalents
| Base value | BTU per hour | Tons of refrigeration | kcal per hour |
|---|---|---|---|
| 1 W | 3.41214 | 0.000284345 | 0.859845 |
| 1 kW | 3,412.14 | 0.284345 | 859.845 |
| 1 MW | 3,412,142 | 284.345 | 859,845 |
| 1 hp | 2,544.43 | 0.212036 | 641.186 |
| 1 PS | 2,509.63 | 0.209136 | 632.415 |
| 1 BTU/h | 1 | 0.0000833333 | 0.251996 |
| 1 TR | 12,000 | 1 | 3,023.95 |
| 1 kcal/h | 3.96832 | 0.000330693 | 1 |
Essential Power Conversion Formulas
Prefer formulas to tables? These are the exact relationships the converter applies — the same ones printed on its formula line after every calculation:
- Universal rule: result = value × (watts per source unit ÷ watts per target unit)
- kW to hp: hp = kW × 1.34102209 | hp to kW: kW = hp × 0.745699872
- kW to PS: PS = kW × 1.35962162 | PS to kW: kW = PS × 0.73549875
- hp to PS: PS = hp × 1.01386967 | PS to hp: hp = PS × 0.98632007
- kW to BTU/h: BTU/h = kW × 3,412.14163 | BTU/h to kW: kW = BTU/h × 0.00029307107
- Tons to kW: kW = TR × 3.51685284 | kW to tons: TR = kW × 0.284345136
- Tons to BTU/h: BTU/h = TR × 12,000 (exact by definition)
- kW to kcal/h: kcal/h = kW × 859.845227 | kcal/h to kW: kW = kcal/h × 0.001163
- kVA to kW: kW = kVA × power factor | kW to kVA: kVA = kW ÷ power factor
- Torque to power (SI): W = torque (N·m) × angular speed (rad/s)
- Torque to power (imperial): hp = torque (lb·ft) × RPM ÷ 5,252
How to Use Our Free Power Unit Converter
The tool at the top of this page was built by the Tooliqo team specifically for the situations described in this article, and a few deliberate design decisions make it different from the generic converters floating around the web.
- Type your value. The field accepts everything real people type: Western digits, Eastern Arabic digits (٥ works just as well as 5), and both decimal styles — "1.5" and "1,5" are read correctly.
- Pick your "From" and "To" units. All 40 units are organised into the same five groups used in this article, so you never scroll through an alphabet soup.
- Read the result instantly. There is no Convert button to hunt for — the answer updates live as you type, with up to 12 significant digits, and switches to clean scientific notation (like 1 × 1022) for extreme values.
- Use the extras. The swap button flips your units in one tap. The copy button grabs the full equation as plain text for pasting into emails or spreadsheets. The formula line under the result shows the exact per-unit rate. And the collapsible quick-conversions panel expands with one tap of the arrow to show your value across the eight everyday units simultaneously.
- Choose your language. The interface runs in English, Arabic (with full right-to-left layout), French, Spanish, Chinese and Hindi, and detects your language automatically — with a manual selector in the corner if you prefer another.
Just as important is what the tool does not do. It loads no external fonts, calls no third-party servers, sets no trackers and shows no ads inside the widget. It is a single, self-contained instrument that works identically on a phone in Casablanca and a workstation in Rotterdam, and it is free with no account, today and permanently.
Power Units in Real Life: EVs, Solar, Data Centers and More
Theory is nice; here is where these conversions actually earn their keep in 2026.
Electric vehicle charging
EV charging is described entirely in kilowatts, and the ladder is worth memorising. A regular household socket (Level 1) delivers a trickle of about 1.4–2.3 kW. A dedicated home wallbox (Level 2) manages 7–11 kW in most homes, up to 22 kW on three-phase European supplies. Public DC fast chargers run from 50 kW to a headline-grabbing 350 kW. Convert that top figure and you appreciate the violence of it: 350 kW is about 469 horsepower of pure electrical flow — more power going into the battery than most cars ever send to their wheels. Meanwhile the motor itself is quoted in kW in Europe (regulation) and horsepower in North America (habit), so a "150 kW" motor and a "201 hp" motor are the very same machine.
Solar panels and home batteries
A single modern residential solar panel is rated around 400–450 W; a typical rooftop array lands between 5 and 10 kW of peak power. Note the trap: that kW rating is the instantaneous maximum under standard test conditions, while your daily production is energy — a 5 kW system in a sunny climate might generate 20–25 kWh per day. Inverters and home batteries also carry a power rating in kW (how fast they can deliver) alongside their capacity in kWh (how much they store). Keeping those two straight is half of solar literacy.
Data centers and the AI power boom
If one industry has dragged the megawatt into mainstream headlines, it is artificial intelligence. A traditional server rack drew 5–10 kW; modern AI training racks pull 50–100 kW and beyond, and hyperscale campuses are being announced in the hundreds of megawatts — with the largest projects openly discussed in gigawatts, the historical vocabulary of nuclear plants. When you read "a 1 GW data-center campus," run it through the converter for perspective: that is 1,341,022 horsepower of continuous draw, or the cooling equivalent of about 284,345 tons of refrigeration. The ice-block ghosts would be dizzy.
Generators and backup power
Generator shopping is the natural habitat of the kVA-to-kW conversion. Add up the real wattage of what you must run — a 2.2 kW pump, 1.5 kW of lighting and electronics, a 1.2 kW refrigerator compressor with its start-up surge — apply the 0.8 power factor rule, and you will know whether the "8 kVA" unit on sale (about 6.4 kW real) actually covers you. Thousands of undersized generators are returned every year over this one confusion.
Your own body
Humans are power plants too, and the numbers are humbling fun. At rest, your body dissipates about 100 W of heat — you are, thermally speaking, a bright old incandescent bulb. A fit amateur cyclist can hold roughly 200–250 W for an hour; Tour de France professionals sustain over 400 W in time trials; and elite track sprinters spike beyond 1,900 W for a few pedal strokes — about 2.5 horsepower, briefly out-powering Watt's original mill horse. Fitness platforms report all of this in watts, which is why cycling nerds are the only people at a dinner party who already know their personal conversion to horsepower.
Common Mistakes When Converting Power Units
After building this tool and writing this guide, we can rank the errors we see most often. Check yourself against the list:
- Mixing up kW and kWh. Power versus energy — the number one confusion in the field. If time is involved in what you are describing, you probably mean kWh.
- Treating kVA as kW. Only true at power factor 1.0. For motors, compressors and generators, assume 0.8 unless the nameplate says otherwise.
- Dropping the "/h" from BTU. A BTU is energy; a BTU per hour is power. Air conditioners are rated in BTU/h even when the label forgets to say so.
- Confusing hp with PS. They differ by about 1.4%. On a 400-horsepower car that is a 5–6 horsepower discrepancy — enough for a spec-sheet argument, and exactly why brochures pick whichever unit reads bigger.
- Rounding too early. Using 0.75 instead of 0.7457 for hp-to-kW seems harmless until it compounds across a fleet calculation. Use full-precision factors (or let the converter carry 12 significant digits for you) and round only at the end.
- Assuming all horsepowers are car-sized. One boiler horsepower is 13.15 mechanical horsepower. Industrial spec sheets bite the unwary.
Frequently Asked Questions About Power Unit Conversion
How many watts are in one horsepower?
One mechanical (imperial) horsepower equals exactly 745.699872 watts, or about 0.7457 kW. One metric horsepower (PS) is slightly smaller at 735.49875 watts. When someone says "horsepower" without qualification in an English-speaking context, they almost always mean the mechanical one.
What is the formula to convert kW to hp?
Multiply kilowatts by 1.34102 to get mechanical horsepower (hp = kW × 1.34102), or by 1.35962 to get metric horsepower. Going the other way, multiply hp by 0.7457 to get kW. For example, a 110 kW engine produces 147.5 hp.
What is a ton of refrigeration, and why is it 12,000 BTU/h?
It is the cooling rate delivered by melting one short ton (2,000 lb) of ice over 24 hours. Ice absorbs 144 BTU per pound as it melts, so 2,000 × 144 = 288,000 BTU per day, which is 12,000 BTU per hour — equal to about 3.517 kW. The unit is a living fossil from the 19th-century ice trade.
What is the difference between kW and kVA?
kW measures real power (useful work); kVA measures apparent power (total voltage-times-current flow). They are linked by the power factor: kW = kVA × PF. A 100 kVA transformer feeding motors at PF 0.85 delivers about 85 kW of real power. They are equal only for purely resistive loads like heaters.
Is PS the same as horsepower?
Almost, but not quite. PS (Pferdestärke, metric horsepower) equals 0.98632 mechanical hp — about 1.4% less. A car listed at 300 PS produces roughly 296 hp. European and Japanese brochures favour PS; American ones use hp; EU regulators increasingly require kW.
How many BTU per hour are in 1 kW?
Exactly 3,412.14 BTU/h. This is the everyday bridge between metric heat-pump specs and North American air-conditioner ratings: a 5 kW heating output is about 17,061 BTU/h, and an 18,000 BTU/h unit delivers about 5.28 kW.
What is the difference between kW and kWh?
kW is a rate (power); kWh is an amount (energy). A 2 kW heater running for 3 hours consumes 6 kWh. Utilities bill energy (kWh); breakers, chargers and appliances are limited by power (kW). Our converter handles power; energy units belong in an energy converter.
What power units do EV chargers use?
Kilowatts, universally. Home charging is typically 7–11 kW, public DC fast charging 50–350 kW. Divide your battery's capacity in kWh by the charger's kW to estimate charging time: a 77 kWh battery on an 11 kW wallbox needs roughly 7 hours from empty (real-world charging curves add some time near full).
How much power does a human body produce?
About 100 W of heat at rest. Sustained athletic output ranges from 150–250 W for fit amateurs to 400+ W for elite endurance athletes, with sprint peaks near 1,900–2,000 W — around 2.5 horsepower for a couple of seconds.
Why does the converter sometimes show scientific notation?
Because honest numbers beat unreadable ones. Convert 1 petawatt to ergs per second and the answer is 10,000,000,000,000,000,000,000 — so the tool displays it as 1 × 1022 instead. The threshold kicks in above 1015 and below 10−9, keeping every result legible while preserving full precision on the copy button.
Final Thoughts
Power units are a 250-year-old conversation between steam engineers, ice merchants, electricians and physicists — which is why we ended up with five horsepowers, a ton that weighs nothing and a watt that hides inside a joule. Once you know that every one of them is just a fixed number of watts, the whole zoo becomes one simple multiplication.
Scroll back up, try the power unit converter with a number from your own life — your car's kW rating, your AC's BTU/h, your generator's kVA — and keep this page bookmarked for the tables and formulas. It is free, private, works in six languages, and it was built to be the last power conversion tool you ever need. You will find more free converters and calculators like this one across Tooliqo.co.