Are US and UK gallons the same?
No. A US gallon is 3.78541 L; an imperial (UK) gallon is 4.54609 L. The imperial gallon is about 20% larger.
Volume calculator
Volume converter
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Volume measures the three-dimensional space an object or fluid occupies. The SI derived unit is the cubic meter (m³); the most common practical unit is the liter (L), defined as exactly 1 cubic decimeter (1 L = 0.001 m³). Common volume units include milliliters and liters (metric) and fluid ounces, cups, pints, quarts, and gallons (US customary), with separate imperial (UK) versions of the same names.
Example volume conversions
1 liter33.814 US fl oz, 0.2642 US gal, 0.220 imperial gal
1 US gallon3.78541 L, 128 US fl oz
1 imperial (UK) gallon4.54609 L, 160 imperial fl oz
1 US cup236.588 mL, 8 US fl oz
Open the live volume converter for any input value.
Metric volume units
The liter is the practical metric volume unit. 1 liter equals exactly 1 cubic decimeter (10 cm × 10 cm × 10 cm) and contains 1,000 milliliters. The cubic meter, 1,000 times larger, is the SI base. For everyday measurements: a soda can is 355 mL, a wine bottle is 750 mL, a typical car fuel tank is 50-70 L.
Decimal prefixes work the way they do everywhere else in SI: 1 microliter (μL) = 10^-6 L is the lab-pipette scale, 1 cubic centimeter (cc) = 1 mL is identical to a milliliter (the 'cc' notation appears in medicine and engine displacement).
US customary vs imperial (UK) volume
The US customary and imperial systems share unit names but use different sizes. The US fluid ounce is 29.5735 mL; the imperial fluid ounce is 28.4131 mL. The US pint is 16 fl oz (473.176 mL); the imperial pint is 20 fl oz (568.261 mL). The US gallon is 3.78541 L; the imperial gallon is 4.54609 L. Whenever you see a recipe, fuel spec, or product listing, the source country determines which definition applies.
This divergence dates to the 1707 establishment of the 'wine gallon' in England, which the US inherited and kept. Britain redefined the imperial gallon in 1824 in terms of the volume of 10 pounds of water at 62°F, which worked out to about 4.546 L. The US never adopted the new definition.
Cooking measurements
Cup measurements travel poorly across regions. The US cup is 8 US fluid ounces, or 236.59 mL. The metric cup (used in Australia and most cookbooks outside the US) is exactly 250 mL. Old British cups were 10 imperial fluid ounces (about 284 mL), but modern UK baking generally uses weight in grams instead of cups.
For precise baking, weight is more reliable than volume because flour and sugar pack differently depending on humidity and how the cup is filled. Most contemporary recipe sites publish both volume and weight for this reason.
Common volume conversions
| From | Equivalent |
|---|---|
| 1 liter | 33.814 US fl oz, 0.2642 US gal, 0.220 imperial gal |
| 1 US gallon | 3.78541 L, 128 US fl oz |
| 1 imperial (UK) gallon | 4.54609 L, 160 imperial fl oz |
| 1 US cup | 236.588 mL, 8 US fl oz |
| 1 metric cup | 250 mL (exact) |
| 1 US fluid ounce | 29.5735 mL |
| 1 imperial fluid ounce | 28.4131 mL |
| 1 US pint | 473.176 mL, 16 US fl oz |
| 1 cubic meter | 1,000 L, 264.172 US gal |
| 1 milliliter | 0.0338 US fl oz, 1 cm³ (exact) |
Frequently asked questions
Is a cup the same in every country?
No. US recipes use a 236.59 mL cup; metric (Australian and most international) recipes use a 250 mL cup; older UK recipes used a 284 mL cup but modern UK baking typically uses weight.
How many mL is 1 fluid ounce?
It depends. 1 US fl oz is 29.5735 mL; 1 imperial fl oz is 28.4131 mL. Always check which definition the source uses.
Is 1 mL the same as 1 cc?
Yes. 1 milliliter (mL) and 1 cubic centimeter (cc, cm³) are identical units. 'cc' is common in medicine and engine specifications.
How do I convert volume of dry ingredients to weight?
There's no universal factor because density varies by ingredient. 1 US cup of all-purpose flour weighs roughly 120-125 g; 1 cup of granulated sugar is about 200 g; 1 cup of water is exactly 236.59 g. Use a kitchen scale for accuracy.
Popular volume conversions
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