Oz to Ml Converter — Fluid Ounces to Milliliters

How to convert fluid ounces to milliliters

Multiply U.S. fluid ounces by 29.5735:

milliliters = fluid ounces × 29.5735295625

8 fl oz × 29.5735 = 236.59 mL. The U.S. fluid ounce is defined as 1/128 of a U.S. gallon, so the factor is exact. To go the other way, divide by 29.5735, or use the mL to fluid ounces converter.

Small amounts keep their precision: 0.5 fl oz is 14.79 mL, not 15.

Bottles, cans and cups

U.S. size	Milliliters	Common item
1 fl oz	29.57 mL	a “pony” shot
3.4 fl oz	100.55 mL	carry-on liquid limit
4 fl oz	118.29 mL	small baby bottle
8 fl oz	236.59 mL	1 cup, baby bottle
12 fl oz	354.88 mL	soda or beer can
16 fl oz	473.18 mL	1 pint, tall can
16.9 fl oz	499.79 mL	500 mL water bottle
20 fl oz	591.47 mL	soda bottle
32 fl oz	946.35 mL	1 quart
33.8 fl oz	999.59 mL	1-liter bottle
64 fl oz	1,892.71 mL	half gallon
128 fl oz	3,785.41 mL	1 gallon

For cups as the main answer, see ounces to cups. To convert a list, open Convert a list of values and paste the fluid ounces one per line.

Ounces, cups, pints, quarts and gallons

U.S. liquid measures double at each step, which makes them easy to convert in fluid ounces first:

8 fl oz = 1 cup = 236.6 mL
16 fl oz = 1 pint = 473.2 mL
32 fl oz = 1 quart = 946.4 mL
128 fl oz = 1 gallon = 3,785.4 mL

So a quart is just under a liter and a gallon is 3.785 liters; for larger volumes, see liters to gallons.

Why labels say 1 oz = 30 mL

On Nutrition Facts panels, the FDA requires household measures to be rounded to convenient metric values: 1 fluid ounce = 30 mL, 1 cup = 240 mL, 1 tablespoon = 15 mL, 1 teaspoon = 5 mL (21 CFR 101.9). That is why a can labeled 12 fl oz may list “355 mL” on the front but serving sizes in multiples of 30 mL on the back. For measuring and recipes, use the exact 29.57 mL.

Fluid ounces vs. ounces of weight

A fluid ounce measures volume; an ounce measures weight (28.35 g). For water they nearly match — a fluid ounce of water weighs about 1.04 oz — but for honey, oil or flour they do not. If a recipe gives an ingredient in ounces and it is a dry solid, it is weight: use ounces to grams, or ounces to pounds for larger amounts.

Frequently asked questions

How many mL is 1 oz?

29.57 mL for a U.S. fluid ounce (29.5735295625 mL exactly). A UK fluid ounce is smaller: 28.41 mL.

How many mL is 8 oz?

236.59 mL — one U.S. cup. A 4 fl oz bottle is 118.29 mL.

Is 16.9 oz 500 mL?

Yes, to within a fraction of a milliliter: 16.9 fl oz is 499.79 mL. Water bottles sold as 500 mL are labeled 16.9 fl oz in the U.S.

Is 1 oz 30 mL?

Only on food labels. The FDA lets Nutrition Facts panels round a fluid ounce to 30 mL (21 CFR 101.9). The actual U.S. fluid ounce is 29.57 mL, about 1.4% less.

Is a UK fluid ounce the same?

No. A UK (imperial) fluid ounce is 28.41 mL, about 4% smaller than the U.S. fluid ounce. British recipes and older UK packaging use it.

Is 3.4 oz 100 mL?

Close: 3.4 fl oz is 100.55 mL. The TSA carry-on limit is written as 3.4 ounces (100 milliliters) per container.