AnyTool
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How do I convert volume between litres, gallons, cups and millilitres?

Type a value into AnyTool Volume Converter and pick the units. It instantly converts both ways between litres, millilitres, cubic metres, cubic feet, US gallons, imperial gallons, US and imperial pints, cups, fluid ounces, tablespoons, teaspoons and oil barrels, keeping US and imperial units clearly separate, and shows the value in every unit at once in a copyable table. Everything is calculated in your browser, so nothing is uploaded.

  • Live two-way conversion — type in either field and the other updates
  • Metric (mL, cm³, L, m³, km³) plus US customary and imperial (UK) units
  • US and imperial units of the same name are labelled separately, never mixed
  • Exact factors through a litre base (1 US gallon = 3.785411784 L, 1 imperial gallon = 4.54609 L)
  • 100% in your browser — no upload, no signup, works offline

What is

Volume Conversion

Volume conversion changes a measurement of capacity from one unit to another — for example litres to gallons. Each unit relates to a litre base by a single exact factor, so any unit converts to any other by multiplying through the base. A key pitfall is that US customary and imperial (UK) units of the same name differ: a US gallon is 3.785411784 litres while an imperial gallon is 4.54609 litres, about 20% larger.

Converters

Related terms

Litres to gallonsUS gallon vs imperial gallonMillilitres to cupsFluid ounce

Frequently Asked Questions

A US gallon is 3.785411784 litres; an imperial (UK) gallon is 4.54609 litres.

It depends which gallon you mean. A US liquid gallon is defined as 231 cubic inches, exactly 3.785411784 litres. An imperial (UK) gallon is exactly 4.54609 litres, about 20% larger. So to convert US gallons to litres multiply by 3.785411784, and for imperial gallons multiply by 4.54609. AnyTool labels both so you never confuse them.

An imperial gallon (4.54609 L) is about 20% larger than a US gallon (3.785411784 L).

A US gallon is 3.785411784 litres and an imperial (UK) gallon is 4.54609 litres, so the imperial gallon is roughly 20% larger — one imperial gallon equals about 1.20095 US gallons. US and imperial pints, quarts and fluid ounces differ too (a US fluid ounce is about 4% larger than an imperial one), which is why AnyTool keeps every customary unit explicitly tagged "US" or "Imperial".

A US customary cup is 236.5882365 millilitres, which is 8 US fluid ounces.

A US legal/customary cup is exactly 236.5882365 millilitres, equal to 8 US fluid ounces or one-sixteenth of a US gallon. A US fluid ounce is 29.5735295625 millilitres, a US tablespoon is 14.787 mL and a US teaspoon is 4.929 mL. These differ from metric cups (250 mL) and imperial measures, so AnyTool uses the exact US customary definitions.

No. Every calculation runs in your browser, so nothing is sent to a server and it works offline.

AnyTool Volume Converter computes every result locally in JavaScript using exact factors through a litre base. No value is uploaded, there is no tracking, and the page keeps working offline after the first load.

Detailed Explanation

Methodology

How the Volume Converter Works

AnyTool Volume Converter performs every calculation in the browser. Each unit declares a single exact factor relating it to a shared litre base, so any unit converts to any other through litres without an N-by-N formula table. The factors are the internationally-agreed definitions: one cubic metre is 1000 L, one US gallon is 3.785411784 L (231 cubic inches), one imperial gallon is 4.54609 L, one US cup is 236.5882365 mL and one US fluid ounce is 29.5735295625 mL. A value is converted to the litre base and then back into the target unit.

  • Nineteen units spanning metric, US customary and imperial (UK) volume
  • The litre is the shared base; each unit defines one exact factor
  • Conversion is value to base to value, so any unit maps to any other
  • Editing either field converts both directions live
  • All arithmetic is client-side JavaScript — no server round-trip
How It Works

US vs Imperial: the Key Pitfall

The most common error in volume conversion is mixing US customary and imperial (UK) units of the same name, because they are different sizes. An imperial gallon (4.54609 L) is about 20% larger than a US gallon (3.785411784 L), and a US fluid ounce (29.5735295625 mL) is about 4% larger than an imperial fluid ounce (28.4130625 mL). To prevent this, AnyTool labels every customary unit explicitly — "US gallon" versus "Imperial gallon", "US pint" versus "Imperial pint", "US fluid ounce" versus "Imperial fluid ounce" — and a reference note states the differences directly.

  • 1 US gallon = 3.785411784 L; 1 imperial gallon = 4.54609 L (~20% larger)
  • 1 US fl oz = 29.5735295625 mL; 1 imperial fl oz = 28.4130625 mL
  • 1 US pint = 0.473176473 L; 1 imperial pint = 0.56826125 L
  • Every US and imperial unit is explicitly labelled to avoid confusion
  • Culinary units (US cup, tablespoon, teaspoon) use exact US customary definitions
Privacy & Security

Privacy and Offline Use

Because all conversion runs in the browser, no value is sent to a server, there is no account or tracking, and the page works offline after first load. The converter is built on a shared, unit-tested conversion engine that other AnyTool unit converters reuse, so behaviour is consistent across the site.

Volume conversion: in-browser (AnyTool) vs typical online converters
CapabilityAnyToolTypical online converters
ProcessingRuns in your browserOften server-side
Units19 metric, US customary and imperialOften a smaller fixed set
US vs ImperialClearly labelled and separatedFrequently ambiguous or unlabelled
Two-way inputEdit either field, both updateUsually one-direction with a button
All units at onceYes, copyable tableOften one target at a time
Works offlineYes (PWA)No
Cost / signupFree, no signupOften ad-heavy or gated

AnyTool converts every unit locally through a litre base and uploads nothing, keeping US and imperial units distinct.