How many milliliters are in a US fluid ounce?

1 fl oz = 29.5735 mL. To convert any amount, multiply by 29.5735.

How do you convert US fluid ounces to milliliters?

Multiply the number of US fluid ounces by 29.5735 to get milliliters. The formula is shown in the "How it's calculated" section above.

Where does the conversion factor come from?

It's a published international standard. Most are defined exactly by international agreement (e.g. 1 inch = 25.4 mm exactly, 1 lb = 0.45359237 kg exactly). Source citations are listed under the formula above.

Unit converter — Volume

US fluid ounces to milliliters converter

Convert US fluid ounces (fl oz) to milliliters (mL). Source-cited conversion factor, exact to the displayed precision.

Results are mathematically exact for the displayed precision. How we calculate.

How it's calculated

Convert US fluid ounces to milliliters— the formula

US fluid ounces convert to milliliters by multiplying by the published conversion factor. The factor below is exact to the precision shown, sourced from the citation under the formula.

mL = fl oz × 29.5735

fl oz = mL × 0.033814

Metric volumes per BIPM SI definitions. US customary volumes per NIST Handbook 44: 1 US gal = 3.785411784 L exactly; 1 fl oz = 1/128 US gal.

Questions

Frequently asked questions

How many milliliters are in a US fluid ounce?
1 fl oz = 29.5735 mL. To convert any amount, multiply by 29.5735.
How do you convert US fluid ounces to milliliters?
Multiply the number of US fluid ounces by 29.5735 to get milliliters. The formula is shown in the "How it's calculated" section above.
Where does the conversion factor come from?
It's a published international standard. Most are defined exactly by international agreement (e.g. 1 inch = 25.4 mm exactly, 1 lb = 0.45359237 kg exactly). Source citations are listed under the formula above.