US Fluid Ounces to Milliliters Converter (fl oz to mL)

Fluid ounces are how the US labels drinks, cough syrup, shampoo and recipe liquids, but measuring jugs, medicine syringes and product specifications in most of the world are marked in milliliters. The US fluid ounce is defined through the gallon, with 128 of them making one, which puts it at exactly 29.5735295625 mL; a 12 fl oz can of soda therefore holds just under 355 mL.

Many US bottles are filled to a round metric size and labeled in fluid ounces afterward, which explains odd figures such as 16.9 fl oz (500 mL) and 25.4 fl oz (750 mL). The chart includes those label values and adds a column of UK fluid ounces, which are about 4% smaller than US ones.

How to use this tool

1. Type a value in the US Fluid Ounce box to see it in milliliters, or type in the Milliliter box to convert the other way.
2. Press ⇄ to swap the two units, or Load example for a typical value.
3. Check the charts below for common values; for other units, open the Volume converter.

Formula

Milliliter (mL) = US Fluid Ounce (fl oz) × 29.5735295625

US Fluid Ounce (fl oz) = Milliliter (mL) × 0.0338140227018

Both factors come from exact definitions: 1 milliliter = 0.0338140227018 US fluid ounces and 1 us fluid ounce = 29.5735295625 milliliters (shown to 12 significant digits).

Example

Two conversions worked with the same factors the converter uses:

20 fl oz × 29.5735295625 ≈ 591.471 mL

1000 mL × 0.0338140227018 ≈ 33.814 fl oz

US Fluid Ounce to Milliliter chart

Common values from US fluid ounces to milliliters, rounded to four decimal places.

Milliliter to US Fluid Ounce chart

The reverse direction for values people often look up.

Drink portions and bottles labeled in US fluid ounces

Quick mental estimate

Multiply by 30, then take away 1.5% of the result: 12 fl oz → 360 − 5.4 ≈ 355 mL. Together the two steps use a factor of 29.55, within 0.1% of the exact value; stopping after the first step leaves you about 1.4% high.

Use the converter or the charts when the exact figure matters.

The two units

US Fluid Ounce (fl oz): The US fluid ounce is 1/128 of a US gallon, exactly 29.5735295625 mL. It measures liquid volume on US drink and medicine labels and is not the same as the ounce of weight.

Milliliter (mL): A milliliter is one thousandth of a liter and exactly the same volume as one cubic centimeter. There are 1,000 microliters in a milliliter and 1,000 milliliters in a liter.