Volume Converter

Convert volume between metric, US, and UK units — litres, mL, gallons, pints, cups, fluid ounces.

100% Browser-Based • Local Processing

How this conversion works

The relation

Worked example
    4

    Common volume conversions

    LitresUS gallons
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    🔒 Local Processing. The values you enter never leave your device.

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    🌐 Fully Client-Side. Runs instantly in your browser.

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    ⚡ No accounts. No API keys. Just open and use.

    Browser Based

    🚀 No installs, no sign-ups, no conversion limits.

    Overview

    What is a Volume Converter?

    > Volume Converter converts capacity between metric, US, and UK units — litres, millilitres, gallons, pints, cups, and fluid ounces. It labels US and UK units separately, because they differ: a US gallon is 3.785 litres, while a UK gallon is 4.546 litres. The exact factor is shown, and it works offline. ---

    ### H2: Convert volume between metric, US, and UK units — without mixing them up

    Volume is the sneakiest set of units, because the same words mean different amounts on different sides of the Atlantic. A US recipe's "cup" isn't a UK cup; a US gallon of fuel isn't a UK gallon; and a US pint is noticeably smaller than a UK pint. Convert with the wrong system and you can be off by a fifth or more — enough to ruin a recipe or misjudge fuel economy.

    This converter fixes that by keeping the systems clearly separate. On the metric side you get litres, millilitres, cubic metres, and cubic centimetres. On the US side, gallons, quarts, pints, cups, fluid ounces, tablespoons, and teaspoons. And on the UK/imperial side, gallons, pints, and fluid ounces — each labelled so you always know which one you've picked. Type a value, choose *from* and *to*, and the answer appears instantly, with a swap button and an all-units table that shows every unit at once.

    The tool shows the exact factor behind each result. A US gallon is 3.785411784 litres by definition (231 cubic inches), while a UK gallon is 4.54609 litres — so it states which one it used, letting you verify the number instead of trusting a guess. Even fluid ounces differ: a US fluid ounce is about 29.57 mL, a UK one about 28.41 mL.

    For cooking, be aware that "cup" isn't standardised worldwide (US 236.6 mL, metric 250 mL, UK 284 mL), and that dry ingredients don't convert to volume the same way liquids do. For ingredient-aware measures like flour or sugar, use the Cooking Measurement Converter. Everything here runs on your own device using fixed factors — nothing is uploaded, and no connection is needed once the page has loaded.

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    Guide

    How to use the Volume Converter

    Step 1: Enter your value. Type the number you want to convert into the input box

    Decimals are fine.

    Step 2: Pick the "from" unit. Choose your starting unit — and if it's a gallon, pint, or fluid ounce, make sure you've selected the right US or UK version

    Pick the "from" unit. Choose your starting unit — and if it's a gallon, pint, or fluid ounce, make sure you've selected the right US or UK version.

    Step 3: Pick the "to" unit. Choose the unit you want the answer in — again, mind US vs UK

    The result updates instantly.

    Step 4: Read the result and the factor. The converted value appears with the exact relationship used (for example, 1 US gal = 3.785411784 L), so you can verify it

    Read the result and the factor. The converted value appears with the exact relationship used (for example, 1 US gal = 3.785411784 L), so you can verify it.

    Step 5: Copy, swap, or expand. Use Copy to grab the number, the swap button to reverse the direction, or open the all-units table to see your value across metric, US, and UK units

    Adjust the decimal places for more precision.

    Screens

    Volume Converter in action

    Volume converter turning 5 US liquid gallons into 18.9271 litres, with the note underneath reading that one US gallon is exactly 3.785411784 litres.
    Converting, with the exact factor underneath
    The volume converter unit list open where the US liquid group ends and the imperial group begins, so a US gallon and an imperial gallon are never mistaken for each other.
    The unit list, with US and imperial measure kept apart
    The US gallons to litres reference table listing common values side by side beneath the converter.
    The reference table for the pair on screen
    The volume converter on a phone screen, the two panes stacked with the swap control between them.
    The same tool on a phone
    Support

    Frequently Asked Questions

    How many litres are in a gallon?

    It depends on the gallon. A US gallon is 3.785411784 litres (about 3.79 L). A UK, or imperial, gallon is 4.54609 litres (about 4.55 L) — roughly 20% larger. So "5 gallons" is 18.9 L in the US but 22.7 L in the UK. Always pick the right system; the tool labels both and shows the factor.

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    Is a US gallon the same as a UK gallon?

    No. A US gallon (3.785 L) is about 20% smaller than a UK/imperial gallon (4.546 L). They just share a name. This matters most for fuel: "40 miles per gallon" in the US isn't the same efficiency as 40 mpg in the UK. The converter keeps US and UK gallons as separate, labelled units so you never mix them up.

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    How many millilitres are in a cup?

    For a US cup, 236.588 mL (usually rounded to 240 mL in nutrition labelling). A metric cup is 250 mL, and a UK cup is about 284 mL. Because "cup" isn't standardised worldwide, the tool lets you choose which one you mean. For ingredient-based baking, the Cooking Measurement Converter is more precise.

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    Is a US pint the same as a UK pint?

    No. A US pint is 473 millilitres (16 US fluid ounces), while a UK pint is 568 millilitres (20 imperial fluid ounces) — about 20% larger. So a "pint" of beer is noticeably bigger in the UK. Convert with the wrong pint and you'll be off by a fifth, which is why the tool separates them clearly.

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    How many millilitres are in a fluid ounce?

    A US fluid ounce is 29.5735 mL; a UK (imperial) fluid ounce is 28.4131 mL. They're close — within about 4% — but not identical, which trips people up in recipes and dosing. The tool labels which one you're using. Note the fluid ounce measures volume, not weight; that's a different "ounce" entirely.

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    How many tablespoons are in a cup, and teaspoons in a tablespoon?

    In US measures, 16 tablespoons make a cup, and 3 teaspoons make a tablespoon — so a cup is 48 teaspoons. In millilitres, a US tablespoon is about 14.79 mL and a teaspoon about 4.93 mL. These are standard cooking equivalents; the tool converts them precisely, and the Cooking Measurement Converter adds ingredient-aware gram conversions.

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    How do I convert litres to gallons?

    Divide litres by the gallon's size. For US gallons, divide by 3.785411784 (or multiply by 0.264172); for UK gallons, divide by 4.54609 (or multiply by 0.219969). For example, 20 litres is about 5.28 US gallons or 4.40 UK gallons. The tool does this automatically and shows which gallon and factor it used.

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    What's the difference between dry and fluid volume?

    Fluid (liquid) measures capacity for liquids; dry measures are a separate US system for produce and grains. A US dry pint (550.6 mL) is larger than a US liquid pint (473 mL), and dry gallons and quarts differ too. This tool defaults to liquid measures, which cover almost all everyday needs; dry measures are a specialist case.

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    Which cup should I use — US, metric, or UK?

    Match the recipe's origin. Use the US cup (236.6 mL) for American recipes, the metric cup (250 mL) for most modern and Australian recipes, and the UK cup (284 mL) for older British ones. The differences are small but add up across several cups. For flour, sugar, and butter, weigh with the Cooking Measurement Converter instead for best accuracy.

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    Is this converter exact, or does it round the answer?

    The math is exact — it uses defined factors (US gallon = 3.785411784 L, UK gallon = 4.54609 L, US fl oz = 29.5735 mL). Only the *displayed* value is rounded for readability, and you can add decimal places for more precision. The factor and system shown with each result let you verify the figure yourself.

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    What's the formula to convert volume units?

    Convert everything through litres. Multiply your value by its factor to litres (US gallon → ×3.785412, UK gallon → ×4.54609, US cup → ×0.2365882, US fl oz → ×0.02957353), then divide by the target unit's factor. For US gallons to litres it's simply value × 3.785412. The tool applies this two-step method for any pair, keeping US and UK units distinct.

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    Does the tool work offline, and does it upload my data?

    It works fully offline once the page has loaded, and it never uploads anything. All conversions are pure arithmetic using fixed factors, so the calculation happens on your own device — no server, no account, no tracking. That makes it dependable in a kitchen or garage with no signal, and private by design, since there's nothing to send.

    Still have questions?

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