Volume Converter: 49 Units - Liters, Gallons, Cups & More

How many milliliters are in a cup? Is a UK gallon really bigger than a US gallon? And what on earth is an acre-foot? If you have ever stood in the kitchen holding an American recipe and a European measuring jug, or stared at a fuel receipt abroad, you already know that volume conversion is one of those small, everyday problems that refuses to stay solved. This page fixes it for good. Below you will find our free volume unit converter — a fast, private, six-language tool that converts between 49 volume units across the metric, US liquid, US dry, imperial (UK), cooking and land-water systems — followed by the most complete plain-English guide to volume units we could write: exact conversion formulas, quick-reference volume conversion charts, worked examples, the history behind the chaos, and answers to the questions people actually search for.

The volume converter

Type a number, pick your units, and read the answer — it updates as you type. Swap direction with one click, copy the full result, switch to dark mode, or change language from the menu in the corner.

Volume Converter Embed Code for Your Website:

Volume is all around us - it's in the coffee we brew, the water we drink, the fuel that powers our journeys, and the ingredients that bring our recipes to life. Yet, volume speaks in many voices. A liter tells a story that a gallon might not fully capture, and a cup can mean something entirely different depending on where you are in the world. This tool was born from the simple desire to make volume a language everyone can speak fluently.

You can copy this code and embed it on your website, giving your visitors a warm, practical companion that transforms how they think about capacity and space. Whether they're following a cherished family recipe from another country, calculating the fuel needed for a road trip, mixing the perfect cocktail, or solving a science problem, this Volume Converter turns complex conversions into a simple, almost magical experience.

The Volume Converter is a beautifully intuitive, interactive tool that allows your website visitors to instantly convert between milliliters, liters, gallons, quarts, pints, cups, and cubic meters. Simply enter a value in any unit, and watch as all other units update in perfect sync - transforming what could be a confusing calculation into a moment of delightful clarity.

This tool is essential for cooking and recipe blogs, travel and adventure websites, scientific and educational platforms, home improvement and DIY sites, or any space where volume and capacity matter. It's more than a converter - it's a thoughtful gesture that helps people connect across different measurement traditions and ways of understanding the 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 culinary adventures, DIY projects, scientific explorations, or everyday life tips, 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 volume conversions alongside your stories - connecting the numbers to the real-world experiences that bring meaning to measurement.

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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 beautifully, becoming a trusted resource that helps your visitors navigate the world of volume - whether they're adjusting a recipe to serve a crowd, calculating liquid capacity for a project, or simply exploring the fascinating relationships between different units of measurement.

Just add these lines to your website's code, and the Volume Converter will appear instantly, ready to help. It's fully responsive by design, providing a flawless experience on desktops, tablets, and mobile phones.

 <div class="tooliqo-tool" data-tool="volume-converter" data-lang="en"></div>
<script src="https://tools.tooliqo.co/embed.js" async></script>

Note: The Volume 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 volume feel less like a puzzle and more like a conversation. Because when we understand volume better, we connect more deeply with the things that fill our lives - from the meals we share to the journeys we take.

What volume actually means

Volume is the amount of three-dimensional space something occupies. A liter of milk, a cubic meter of concrete and a barrel of crude oil are all answers to the same question — how much room does it take up? — expressed in different units. That is worth pausing on, because volume gets confused with two neighbors constantly. It is not mass: a liter of feathers and a liter of lead occupy the same space but weigh wildly different amounts. And it is not quite capacity either, although the two words are used almost interchangeably: capacity is the volume a container can hold, while volume is the space anything occupies, container or not.

In the International System of Units (SI), the coherent unit of volume is the cubic meter (m³) — the space inside a cube one meter on each side. For daily life the cubic meter is enormous (a thousand liters — you could bathe in it), so the world mostly runs on the liter, which is defined as exactly one cubic decimeter: a cube 10 cm on a side. That single definition is the quiet hero of this whole page, because it welds the "liquid" units (liters, milliliters) to the "geometric" units (cubic centimeters, cubic meters) with no rounding at all: 1 mL = 1 cm³, exactly, and 1,000 L = 1 m³, exactly.

Everything else — gallons, pints, cups, bushels, barrels, acre-feet — is history wearing a lab coat. Each of those units was born in a marketplace, a tavern, a grain exchange or an oil field, and was only later pinned to an exact metric value by law. Once you know each unit's exact size in liters, converting between any two of them is one multiplication and one division. That is precisely what our converter does, 49 units at a time.

How to use the converter

The tool was designed so you never need instructions, but here is the full tour so you can use every part of it:

1. Type a value. The result updates instantly with every keystroke — there is no Convert button to hunt for. The input is forgiving: it accepts a decimal point (3.5), a decimal comma (3,5), scientific notation (2.5e6), and even Arabic-Indic digits (٣٫٥). Click into the field and the current value is selected automatically, ready to be overtyped.
2. Pick the "From" unit. The menu is organized into six labeled groups — Metric, US Liquid, US Dry, Imperial (UK), Cooking (metric) and Other — so you find the right gallon or the right pint in seconds instead of scrolling one long alphabet soup.
3. Pick the "To" unit the same way. The big result appears immediately, followed by a full sentence you can read out loud ("5 Gallon (US) = 18.92705892 Liter") and, just below it, the exact conversion formula for the pair you chose, in both directions.
4. Fine-tune with the keyboard. On a desktop, press ↑ or ↓ to step the value by 1, or hold Shift for steps of 10 — perfect for scanning how a range of values behaves without retyping.
5. Swap, copy, share. The circular swap button reverses the direction instantly. The Copy button grabs the whole result sentence for pasting into a message or a document. And because the tool reads ?value=, ?from= and ?to= from the page address, you can bookmark or share a link that opens with your exact conversion already loaded.

What makes this tool different

There are plenty of volume calculators online. We built this one anyway, because we kept hitting the same four walls with the others — and each wall shaped a feature.

All the gallons, clearly labeled

Most converters list "gallon" once and let you guess which country's gallon you are getting. Ours carries 49 units in six explicit systems: nineteen metric units — the full prefix ladder from petaliter to picoliter plus the cubic family from km³ down to mm³, ten US liquid units including both the 42-gallon oil barrel and the 31.5-gallon US fluid barrel, five US dry units (bushel, peck, dry gallon, dry quart, dry pint), five imperial UK units including the gill, four metric cooking units, and six specialist units — cubic foot, cubic inch, cubic yard, acre-foot, cord and board foot. Ambiguity is the enemy of a converter; labels are the cure.

Six languages, one tool

The interface speaks English, Arabic, French, Spanish, Chinese and Hindi, detects your language automatically, and lays itself out right-to-left for Arabic — not just translated labels, but a properly mirrored interface. Your choice is remembered for next time.

Honest numbers

Every unit is stored at its exact legal definition (you can audit the full list in the master table below), results are computed to twelve significant digits, and extreme values switch to clean scientific notation instead of collapsing into a wall of zeros. The formula line under every result shows you the factor being used, so the tool teaches while it calculates.

Comfortable to live with

A one-tap dark mode for late-night studying, a layout that works from a 4-inch phone to a desktop monitor, keyboard stepping, copy-ready output, shareable deep links, and zero network calls. Small things — until you use a converter twenty times a week.

The universal conversion formula

Every volume conversion on Earth — all of them, no exceptions — reduces to one line. Express both units as their size in liters, then:

That is the entire engine of the converter above. Three worked examples show how it plays out:

• 3 US gallons to UK pints. A US gallon is 3.785411784 L and a UK pint is 0.56826125 L, so: 3 × 3.785411784 ÷ 0.56826125 = 19.9842 UK pints.
• 2.5 cubic meters to US gallons. A cubic meter is 1,000 L: 2.5 × 1000 ÷ 3.785411784 = 660.4301 US gallons — the volume of a small hot tub.
• A 750 mL wine bottle to US fluid ounces. 750 × 0.001 ÷ 0.0295735295625 = 25.3605 fl oz, which is why a "fifth" pours about five 5-ounce glasses.

Because the liter sits in the middle of every calculation, adding a new unit to your mental toolkit only ever costs you one number: its size in liters. Memorize just three — a US gallon is about 3.785 L, a UK gallon about 4.546 L, and a US cup about 237 mL — and you can sanity-check almost any everyday conversion in your head.

Key conversion formulas, both directions

These are the factor pairs the tool displays in its formula line, collected here for the conversions people reach for most. Each line reads in both directions — multiply going one way, divide (or use the second factor) coming back:

• 1 US gallon = 3.785412 liters  ·  1 liter = 0.2641721 US gallons
• 1 UK gallon = 4.54609 liters  ·  1 liter = 0.2199692 UK gallons
• 1 US cup = 236.5882 milliliters  ·  1 milliliter = 0.004226753 US cups
• 1 US fluid ounce = 29.57353 milliliters  ·  1 milliliter = 0.03381402 US fluid ounces
• 1 US quart = 0.9463529 liters  ·  1 liter = 1.056688 US quarts
• 1 UK pint = 568.2613 milliliters  ·  1 milliliter = 0.001759754 UK pints
• 1 cubic meter = 1,000 liters  ·  1 liter = 0.001 cubic meters
• 1 cubic foot = 28.31685 liters  ·  1 liter = 0.03531467 cubic foots
• 1 cubic inch = 16.38706 milliliters  ·  1 milliliter = 0.06102374 cubic inchs
• 1 oil barrel = 158.9873 liters  ·  1 liter = 0.006289811 oil barrels
• 1 US bushel = 35.23907 liters  ·  1 liter = 0.02837759 US bushels
• 1 acre-foot = 1,233.482 cubic meters  ·  1 cubic meter = 0.0008107132 acre-foots

And the internal structure of each family is worth knowing by heart, because it lets you convert within a system without touching a calculator:

US liquid ladder: 1 gal (US) = 4 qt = 8 pt = 16 cups = 32 gills = 128 fl oz = 256 tbsp = 768 tsp

US dry ladder: 1 bushel = 4 pecks = 8 dry gallons = 32 dry quarts = 64 dry pints

Imperial (UK) ladder: 1 gal (UK) = 4 qt = 8 pt = 32 gills = 160 fl oz

Geometric ladder: 1 yd³ = 27 ft³ = 46,656 in³

Timber & land: 1 acre-foot = 43,560 ft³  ·  1 cord = 128 ft³  ·  1 board foot = 1/12 ft³

The 20 most-searched volume conversions

Straight answers to the conversions typed into search engines millions of times a month — every value computed by the exact engine of the tool above:

Quick conversion tables

Two tables cover the vast majority of daily conversions. The first radiates outward from the liter; the second is the one to print and tape inside a kitchen cupboard.

One liter, translated

Kitchen measures in milliliters and fluid ounces

All 49 units: the master reference table

This is the converter's actual internal table — every unit it supports and the exact number of liters each one represents. These are legal definitions, not approximations, which is why some of them carry so many digits.

The metric system: one unit, many prefixes

The genius of metric volume is that it is not really nineteen units — it is one unit wearing nineteen prefixes. Learn the liter and the prefix ladder, and you have learned them all. Each step up or down the ladder (kilo-, hecto-, deca-, deci-, centi-, milli-...) multiplies or divides by ten, so converting 3.7 liters to milliliters is not mathematics, it is moving a decimal point three places: 3,700 mL. Compare that with remembering that a US gallon holds 128 fluid ounces, and you understand why 95% of humanity settled on metric.

A few rungs of the ladder deserve a closer look. The milliliter is the workhorse of medicine, cooking and beverages — identical, remember, to the cubic centimeter. The hectoliter (100 L) survives in European agriculture and brewing statistics: vineyard yields are quoted in hectoliters per hectare, and brewery capacity in thousands of hectoliters. The megaliter (a million liters) and gigaliter are the language of reservoirs and municipal water reports in metric countries — Australia's water authorities publish dam levels in gigaliters. At the extremes, laboratory science runs on microliters and nanoliters (a modern PCR reaction is pipetted in microliters; an inkjet printer fires droplets of a few picoliters), while hydrologists reach for the cubic kilometer — a trillion liters — to describe lakes: Lake Geneva holds roughly 89 of them.

One convention to note: to avoid confusing the lowercase letter l with the digit 1, the liter's symbol may be written as a capital L, and this tool does so throughout. So mL, not ml — same unit, clearer glyph.

US liquid measures: the 231-cubic-inch family

Every US liquid unit descends from a single ancestor: the Queen Anne wine gallon of 1707, defined as exactly 231 cubic inches. When the young United States needed standard measures, it adopted that wine gallon and never left, even after Britain itself moved on in 1824. Pin the gallon at 231 in³ (3.785411784 L exactly) and the whole family falls into place by halving and quartering: the quart is a quarter gallon, the pint half a quart, the cup half a pint, the fluid ounce an eighth of a cup, the tablespoon half a fluid ounce, and the teaspoon a third of a tablespoon. The nearly forgotten gill — a quarter pint, 4 fl oz — lives on mainly in old cocktail books and whisky lore.

Then there are the barrels, plural, and this is where expensive mistakes happen. The oil barrel (bbl) is exactly 42 US gallons — 158.987 liters — a size inherited from 19th-century Pennsylvania crude shipped in tierce casks; world oil markets still price in it, even though actual oil moves through pipelines and tankers. The US fluid barrel for most other liquids is 31.5 gallons (119.24 L), and federal beer regulations use yet another barrel of 31 gallons. Our converter lists the oil barrel and the fluid barrel as two separate, clearly named units precisely so that "barrel" can never ambush you.

Scale intuition helps here: a US gallon is the big milk jug; a quart is the carton of broth; a pint is the ice-cream tub or the blood-donation bag; a fluid ounce is two tablespoons, the size of an espresso shot minus a splash.

US dry measures: the bushel's family

Here is the trap almost nobody warns you about: the United States runs two parallel measurement families, and they share names. Liquid quarts and pints come from the wine gallon; dry quarts and pints come from the Winchester bushel, an English grain measure standardized under Henry VII and defined today as exactly 2,150.42 cubic inches — 35.23907 liters. Divide the bushel by four and you get the peck (8.81 L, the unit Peter Piper picked his pickled peppers in); divide again for the dry gallon, again for the dry quart (1.101 L), and once more for the dry pint (0.551 L).

The practical consequence: a dry quart is about 16% larger than a liquid quart. The little basket of strawberries or cherry tomatoes sold as a "pint" at an American farmers market is a dry pint — noticeably more than a pint of cream. US agriculture still reports harvests in bushels (corn futures in Chicago trade in 5,000-bushel contracts), and grain bushels double as weight units by law — a bushel of shelled corn is 56 pounds, of wheat 60 — one more reason to keep dry and liquid measures firmly apart, and one more reason this converter labels its US Dry group explicitly.

Imperial (UK) measures: bigger by design

In 1824, Britain swept away its tangle of wine gallons, ale gallons and corn gallons and legislated one imperial gallon for everything, originally defined as the volume of ten pounds of water at 62 °F. Today it is fixed in metric as exactly 4.54609 liters — about 20% larger than the US gallon that had already emigrated across the Atlantic. The subdivisions kept the familiar names but not the familiar sizes: an imperial quart is 1.1365 L, an imperial pint 568.26 mL, and — the real saboteur — the imperial fluid ounce is 28.41 mL versus the US 29.57 mL, because the imperial system puts 20 fluid ounces in a pint where the US puts 16.

Where you will still meet these units: draught beer and milk in the UK are sold by the imperial pint (that is why a proper British pint glass visibly out-classes a US one), UK and Canadian fuel economy is quoted in miles per imperial gallon (making direct comparison with American mpg figures misleading by a fifth), and Canadian recipes from older cookbooks may lean imperial. Whenever a document just says "gallon" or "fl oz", the first question to ask is whose? — and the converter's separate US and UK entries let you test both readings in seconds.

Cooking measures: cups, spoons and drops

Recipes are where volume conversion stops being trivia and starts deciding whether your cake rises. The core problem: the words cup, tablespoon and teaspoon name different volumes in different countries. The US customary cup is 236.588 mL; the metric cup used across Australia, New Zealand, Canada and most modern international recipes is exactly 250 mL; older British books use a 284 mL breakfast cup. Spoons are just as regional: the US tablespoon is 14.79 mL, the metric tablespoon exactly 15 mL — a difference you can ignore — but the Australian tablespoon is 20 mL, a full third larger, which absolutely matters for baking powder, salt or gelatin.

That is why the converter carries the metric kitchen family — metric cup, metric tablespoon, metric teaspoon — as first-class units alongside their US cousins, plus the metric drop (gtt), standardized in pharmacy at 0.05 mL, or 20 drops to the milliliter. The honest advice every serious baker eventually gives: volume is a rough tool for dry ingredients. A cup of flour can weigh anywhere from 120 to 150 grams depending on how it is scooped. Convert liquids with confidence using the tool above; for flour and sugar, when precision matters, a kitchen scale wins. For everything else — broths, milks, oils, syrups — the kitchen table in the quick tables section covers you.

Acre-feet, cords and board feet: volume at work

Beyond kitchens and fuel pumps, whole industries measure space in units most converters ignore — so we included them.

The acre-foot: how the American West counts water

An acre-foot is the volume of water that would cover one acre of land one foot deep: exactly 43,560 cubic feet, which is 1,233,481.838 liters or about 325,851.43 US gallons. It sounds arcane until you read any news story about drought, reservoirs or water rights in California, Arizona or Colorado — allocations from the Colorado River are negotiated in millions of acre-feet, and Lake Mead's level is reported the same way. A handy anchor: one acre-foot supplies roughly two to four typical households for a year. If you follow water news at all, this single unit is the trend-driving reason to bookmark a converter that speaks it.

The cord: firewood's honest measure

Firewood in North America is sold by the cord: a tightly stacked pile 4 ft × 4 ft × 8 ft, or 128 cubic feet (about 3,624.6 liters). Because loosely thrown wood contains far more air, several US states legally require firewood to be advertised in cords or fractions of a cord — knowing the true volume protects you from the vague "truckload."

The board foot: lumber's hybrid

Sawmills and lumberyards price hardwood by the board foot: the volume of a board one foot square and one inch thick — one-twelfth of a cubic foot, 2.3597 liters. Estimating a woodworking project? Multiply length × width × thickness in inches, divide by 144, and you have board feet; or let the converter jump straight between board feet, cubic feet and cubic meters when comparing local and imported timber prices.

The geometric trio

The cubic inch (16.387 mL) survives in engine displacement — a classic American 350 V8 is 350 in³, about 5.7 L. The cubic foot (28.317 L) sizes refrigerators, moving boxes and natural-gas billing. The cubic yard (27 ft³, 764.55 L) is how concrete, mulch, gravel and dumpster capacity are ordered — when a contractor says "a ten-yard skip," this is the yard they mean.

Worked real-world examples

Formulas stick better with stories attached. Here are six conversions people actually perform, worked through the way the tool does them.

1. Scaling an American recipe to metric

The recipe calls for 2¼ cups of milk. Enter 2.25, convert US cups to milliliters: 2.25 × 236.5882365 = 532.32 mL. Round to 530 mL and pour — for liquids, that half-percent rounding is invisible in the result.

2. Sizing an aquarium

European aquarium kit lists a 200 L tank; American forums discuss stocking in gallons. 200 L = 52.834 US gallons — so the care guides written for a "55-gallon" tank are the right ones to read.

3. Fuel abroad

You buy 50 liters of petrol in Europe. That is 13.209 US gallons — but only 10.998 imperial gallons. Comparing the pump price to what you pay at home means picking the right gallon first; get it wrong and your "price per gallon" is off by 20%.

4. Ordering concrete

Your slab needs 2.3 m³ of concrete, but the local supplier quotes by the cubic yard. 2.3 m³ = 3.008 yd³ — just over three yards, so order 3.5 and keep a sensible margin for uneven ground and spillage.

5. Filling a pool

A 50 m³ backyard pool holds 13,208.6 US gallons. At a garden hose's typical 10 gallons per minute, that is roughly 22 hours of filling — and, in a drought-priced water district, a bill worth calculating before you start.

6. Reading water news like a local

A reservoir gains 12,000 acre-feet after a storm. 12,000 × 1,233,481.84 L ÷ 1,000 = about 14.8 million cubic meters — or, switching units in the tool, nearly 3.9 billion US gallons. Suddenly the headline has a size you can feel.

Five mistakes that ruin volume conversions

1. Mixing up US and UK gallons (or fluid ounces). The classic. A UK gallon is 4.54609 L against the US 3.78541 L, and the fluid ounces differ too (28.41 vs 29.57 mL). Fuel economy comparisons, homebrew recipes and shipping quotes all fall to this one. Fix: never convert a bare "gallon" — identify the country first, then pick the explicitly labeled unit in the converter.

2. Using a liquid quart where a dry quart is meant. US produce baskets, grain figures and gardening soil measures use the dry family, 16% larger. If the number describes something poured, use US Liquid; if something heaped, check whether it is US Dry.

3. Treating volume as weight. "A liter is a kilogram" works for cold water and almost nothing else. Recipes converting cups of flour to grams by a water-based rule end up 40% wrong. Volume converts to volume; converting to mass requires the substance's density.

4. Assuming every tablespoon is your tablespoon. US 14.79 mL, metric 15 mL, Australian 20 mL. For potent ingredients — yeast, salt, medicine — the Australian gap is enough to change the outcome. Check the recipe's origin; the converter carries both US and metric spoons so you can translate deliberately.

5. Rounding too early. Convert first, round last. Rounding 1 cup to "240 mL" and then scaling a recipe by six multiplies your rounding error six-fold. The tool keeps twelve significant digits internally precisely so that chained calculations stay honest; do your rounding once, at the end, to the precision the task needs.

Accuracy & rounding: how the converter computes

Under the hood, the tool stores every one of its 49 units as an exact legal definition in liters — the same values printed in the master table. The US gallon is not "about 3.785" but exactly 3.785411784 L, because the inch is defined as exactly 2.54 cm and the gallon as exactly 231 cubic inches. The imperial gallon is exactly 4.54609 L by the UK Weights and Measures Act. Nothing is looked up from a rounded chart; every conversion is a fresh multiplication and division of exact factors.

Results display up to twelve significant digits, with thousands separators for readability. Very large or very small answers — a petaliter in teaspoons, say — switch automatically to scientific notation, which is why the tool can walk the full span from picoliters (10⁻¹² L) to petaliters (10¹⁵ L), twenty-seven orders of magnitude, without losing its footing. When you need fewer digits, round the displayed result yourself as the final step: three significant figures is plenty for cooking, five for engineering estimates, and the full precision is there when a lab report or an audit demands it.

A short history of measuring volume

Volume was one of humanity's first measurements, because it was the tax collector's measurement. Ancient Egypt levied grain in hekats (about 4.8 L) and checked them with official scoops; Babylon sealed standard jars; Greece and Rome shipped wine and olive oil in amphorae so standardized that archaeologists date shipwrecks by their shape. For thousands of years, the container was the unit.

Medieval England turned that into glorious chaos: separate gallons for wine, ale and corn, each with its own political history. Two of them still shape your kitchen. The wine gallon of 1707 (231 in³) crossed the Atlantic and became the US gallon; the Winchester bushel became America's dry measure. Britain itself pressed reset with the Imperial Weights and Measures Act of 1824, creating the larger imperial gallon — which is the moment the US and UK systems permanently diverged while keeping identical names, a prank on posterity that this entire article has been cleaning up after.

Meanwhile, revolutionary France asked a better question: why should units be containers at all? In 1795 the litre was defined as one cubic decimeter — volume derived from length, decimal all the way down. (For a strange interlude between 1901 and 1964, the liter was redefined via the mass of water and turned out to be 1.000028 dm³; science quietly put it back.) Today the liter is an "accepted non-SI unit," the cubic meter is the SI standard, and every gallon, pint, bushel and barrel is legally defined as some exact number of liters — which is the only reason a page like this, and a tool like ours, can promise exactness rather than approximation.

Frequently asked questions

Convert once, understand forever

Volume conversion looks like arithmetic, but it is really translation — between the metric world and the customary one, between the kitchen and the lab, between a Texas oil report and a Rotterdam shipping manifest. Keep the one universal formula in mind, respect the difference between the gallons, and let the converter at the top of this page handle the twelve-digit heavy lifting in your language, on any device, for free. Bookmark it, share a pre-loaded link with a friend mid-recipe, and the next time someone asks how many fluid ounces are in a UK pint, you will not just know the answer — you will know why it is 20 and not 16.