A recipe calling for a gallon means two different amounts depending on which side of the Atlantic wrote it — and the gap is 20%, which is more than enough to ruin the recipe or the fuel-economy figure.
What the Volume Converter does
Converts between metric and US customary volumes, and includes the UK gallon separately at 4.54609 L against the US gallon’s 3.785411784 L.
Every cooking unit here is US — cups, pints, quarts and fluid ounces all differ between the US and UK, and quietly mixing the two is how a recipe fails.
Open the Volume Converter and follow the settings and checks below.
Exact factors, in litres
| Setting | What it means |
|---|---|
| US gallon | 3.785411784 |
| UK gallon | 4.54609 — 20% larger |
| US quart | 0.946352946 |
| US pint | 0.473176473 |
| US cup | 0.2365882365 — about 237 ml |
| US fluid ounce | 0.0295735296 |
| Tablespoon / teaspoon | 0.0147867648 / 0.00492892159 |
| m³ | 1000 |
How to use it
- Enter the volume.
- Choose the units — and check whether a recipe is US or UK before assuming.
- Read the result.
Practical advice
A UK pint is 568 ml and a US pint is 473 ml — a difference of nearly 20%. In a recipe that is the gap between working and not; in a fuel-economy figure it makes a car look dramatically more or less efficient than it is. If a source does not say which system it uses, the spelling usually tells you: "litre" and "colour" mean UK.
Common questions
Why are US and UK gallons different?
They descend from different historical standards and were never reconciled. The US kept an older wine gallon; the UK redefined its gallon in 1824 as the volume of ten pounds of water. The 20% gap has persisted ever since.
Is a cup here US or UK?
US, at about 237 ml. A metric cup is 250 ml and the UK does not really use cups at all, preferring weight. For baking especially, weigh ingredients if you can — it removes the ambiguity entirely.
How much is a UK pint?
About 568 ml, against 473 ml for a US pint. It is why a pint of beer is noticeably larger in Britain, and why converting drinks measures across the Atlantic needs care.
Which units here are metric?
Litres, millilitres and cubic metres. Everything else is US customary apart from the UK gallon, which is listed separately precisely because the ambiguity causes errors.
Useful next tools
- Unit Converter — Length, mass, temperature, area, volume, speed and data.
- Weight Converter — Convert kg, pounds, ounces, stone and grams.
- Length Converter — Convert miles, km, feet, inches, metres and more.
- Area Converter — Convert acres, hectares, square feet and metres.
- Fuel Economy Converter — Convert between MPG, L/100km and km/L.
- Water Intake Calculator — How much water to drink a day by weight, activity and climate.
Vootkit provides a browser calculator and educational guidance. Results depend on the values and units you enter, so verify important financial, academic, safety or professional decisions with an appropriate authoritative source.
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