Fluid Ounces to Milliliters Converter

How it works

mL = US fl oz × 29.5735 · mL = UK fl oz × 28.4131 · litres = mL ÷ 1,000 · cups = US fl oz ÷ 8 · tablespoons = fl oz × 2 · teaspoons = fl oz × 6 · weight (g) = mL × density

A US fluid ounce is exactly 29.5735295625 millilitres, defined as 1/128 of a US gallon, so the conversion is one multiplication. The British imperial fluid ounce is smaller, 28.4130625 mL, because it is 1/160 of an imperial gallon. The gap is about 4%, which matters in large amounts or when you scale up a British recipe. A third unit is used on US nutrition labels, which treat 1 fl oz as 30 mL. Pick the one you have next to the number. You also get litres, US and metric cups, tablespoons, teaspoons, pints, quarts and gallons, a breakdown into US measuring cups and spoons, and, under More options, the weight of the amount for 20 common liquids from water and milk to honey, oil and spirits. Fluid ounces measure volume, so the weight depends on the liquid.

Worked example

A US recipe asks for 6 fl oz of milk. 6 × 29.5735 = 177.4 mL, which is 0.177 L, ¾ cup or 12 tablespoons. Milk weighs about 1.01 g per mL, so that is roughly 183 g. A British recipe that says 6 fl oz means 6 × 28.4131 = 170.5 mL, about 7 mL less.

Sources: NIST — US customary volume units (1 fl oz = 29.573 529 562 5 mL) · FDA — 21 CFR 101.9: household measures on nutrition labels (1 fl oz = 30 mL)

Frequently asked questions