Milliliters ⇄ US Fluid Ounces Converter

How to convert milliliters to US fluid ounces

To convert milliliters to US fluid ounces, divide the value by 29.5735295625, or multiply it by about 0.033814.

fl oz = mL ÷ 29.5735295625

Example: 10 mL ÷ 29.5735295625 = 0.33814 fl oz

How to convert US fluid ounces to milliliters

To convert US fluid ounces to milliliters, multiply the value by 29.5735295625.

mL = fl oz × 29.5735295625

Example: 10 fl oz × 29.5735295625 = 295.735 mL

1 mL = 0.033814 fl oz · 1 fl oz = 29.5735 mL

This page uses US fluid ounces, which are exactly 29.5735295625 milliliters. A UK (imperial) fluid ounce is a little smaller at 28.4130625 mL; the Unit Converter has both. Fluid ounces measure volume, not weight, so they are not the same as ounces on a kitchen scale.

Milliliters and fluid ounces

A milliliter is one thousandth of a liter and exactly the same volume as a cubic centimeter, which is why syringes and engine sizes are sometimes labeled in cc. The US fluid ounce is defined as 1/128 of a US gallon. American drink labels, nutrition facts and recipes use fluid ounces, but most packaging prints both units, and many US bottles are actually filled to round metric sizes.

Cans, bottles and cups

That is why American water bottles carry the odd-looking “16.9 fl oz”: they are 500 mL bottles. In the other direction, the US 12-ounce can is really 354.9 mL and is rounded to 355 mL on the label.

Baby bottles and kitchen measures

Baby bottles are usually marked in both units, with lines such as 60 mL beside 2 oz and 120 mL beside 4 oz. Those pairs are rounded: 4 US fl oz is really 118.3 mL. The gap is small, but it is safest to read one scale consistently and to follow the instructions that come with the formula.

In cooking, a US cup is 8 fl oz (236.6 mL), a tablespoon is half a fluid ounce (14.8 mL) and a teaspoon is 4.9 mL. Other countries use other cups: Australia and New Zealand use a 250 mL metric cup, and Japanese recipes use a 200 mL cup, so “one cup” can differ by 50 mL depending on where the recipe was written.

Quick mental math

• Milliliters to fluid ounces: divide by 30. 500 mL → 16.7 fl oz (exact: 16.9 fl oz), about 1.4% low.
• Fluid ounces to milliliters: multiply by 30. 12 fl oz → 360 mL (exact: 354.9 mL), about 1.4% high. Multiplying by 29.6 instead gets you within 0.1%.

Common mistakes

• Using a metric cup for a US recipe. A 250 mL cup holds 5.7% more than a US cup, which adds up across several cups of liquid.
• Assuming every “ounce” on a menu is the same. Drink sizes in the US are in US fluid ounces; older British recipes use imperial fluid ounces, which are about 4% smaller.
• Rounding before multiplying. Rounding 1 fl oz to 30 mL is fine once, but for a 64 fl oz jug it gives 1,920 mL instead of 1,893 mL.

FAQ

How many fluid ounces are in a liter?

About 33.8 US fl oz, so a liter is a little more than a US quart (32 fl oz, 946 mL).

Is 100 mL the same as 3.4 oz?

Almost: 100 mL is 3.38 fl oz and 3.4 fl oz is 100.6 mL. Airport security rules for liquids in carry-on bags have long used these two figures for the same container limit; check your airport’s current rules before you fly.

Does a fluid ounce of water weigh one ounce?

Nearly. A US fluid ounce of water weighs about 29.6 g, or 1.04 oz. The imperial fluid ounce was designed so that one fluid ounce of water weighs about one ounce.

How many milliliters is a shot?

There is no single standard. In the US a shot is commonly 1.5 fl oz (44 mL), while measures in other countries are typically somewhere between 20 and 40 mL.

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