Volume Converter

Convert metric and imperial volume / liquid measures.

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📖 Read the full guide: Volume Units: US Gallons vs UK Gallons (and Why Recipes Confuse You) In-depth article explaining the math and real-world context. →
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US vs UK Gallons (And Why Recipes Confuse You)

One of the most common volume gotchas in cooking and engineering: 1 US gallon = 3.785 L; 1 UK (imperial) gallon = 4.546 L. The difference is significant — about 20%. The UK pint, quart and fluid ounce all differ from US versions too. Always check which system a recipe or specification uses, especially for:

  • Fuel economy comparisons — UK mpg ≈ US mpg × 0.83 because UK gallons are bigger
  • Cooking recipes — a UK pint of milk is 568 ml; a US pint is 473 ml
  • Beer pints — UK 568 ml, US 473 ml, Australia 570 ml

Useful References

VolumeEquivalent
1 liter1,000 ml = 1 dm³ = 0.001 m³
1 US cup236.6 ml = 8 US fluid oz
1 US tablespoon14.79 ml = 3 teaspoons
1 US teaspoon4.93 ml
1 US fluid ounce29.57 ml
1 US pint473 ml = 2 cups
1 US quart946 ml = 2 pints
1 US gallon3.785 L = 4 quarts
1 UK / Imperial gallon4.546 L
1 Olympic swimming pool~2,500,000 L

Why "Metric Cups" Are Different

To make things worse, several countries use slightly different "cup" measurements:

  • US legal cup (FDA nutrition labels) = 240 ml
  • US customary cup (most recipes) = 236.6 ml
  • Metric cup (Australia, NZ, Canada) = 250 ml
  • UK cup = 284 ml (rarely used in modern UK recipes — they use grams)

For precision in baking, measure by weight (grams) not volume. The NIST metric guide covers official US standards.