Ml to oz converter

Two sizes of fluid ounce

The US fluid ounce is 1/128 of a US gallon: exactly 29.5735295625 mL (NIST Handbook 44). The imperial fluid ounce, used in the UK, is 1/160 of an imperial gallon: exactly 28.4130625 mL (UK Weights and Measures Act 1985). The US ounce is about 4% bigger. The main answer uses US fluid ounces, and the imperial figure is shown beside it.

Worked example

250 mL ÷ 29.5735295625 = 8.4535 US fl oz, or 250 ÷ 28.4130625 = 8.7988 imperial fl oz. Going back, 8 US fl oz is 236.59 mL, which is one US cup.

Labels round

US nutrition labels may count 1 fl oz as 30 mL and 1 cup as 240 mL (FDA labeling rule), so a 12 fl oz can is marked 355 mL. Bottles in Canada and Australia are sold in milliliters, but recipes from the US use US ounces.

Fluid ounces are not weight

A fluid ounce measures volume. To weigh something in ounces, see grams to ounces. For cups, spoons, pints and gallons, see the volume and cooking converter.

A quick check in your head

A US fluid ounce is about 30 mL, so divide milliliters by 30: 500 mL is about 17 fl oz (exactly 16.9).

Rounding

The answer is worked out from the exact definition, then shown to 4 decimal places (6 significant figures for numbers below 1). It says "exactly" only when nothing was rounded.