# US fluid ounces to milliliters converter

> Convert US fluid ounces to milliliters (oz to ml) with the exact factor, a conversion chart and worked steps.

Interactive version: https://www.calcopenly.com/conversion/oz-to-ml
Subject: Unit converters

US fluid ounces are volume measures used on beverage packaging and measuring cups. They are different from ounces of mass and from imperial fluid ounces. Use the labelled US amount as the starting value, and do not infer an ingredient's weight from volume alone.

One US fluid ounce is exactly 29.5735295625 milliliters, so 8 fl oz is 236.588237 mL. To convert oz to ml, multiply by 29.5735295625; to convert back, multiply by 0.0338140227.

The US fluid ounce is 1/128 of a US gallon, exactly 29.5735295625 mL. Because both units are defined exactly, the factor above is exact and the results here carry no conversion error.

## Inputs

- **US fluid ounces (fl oz)**

## Results

- Milliliters (mL) — main result
- Conversion
- 1 mL in US fluid ounces (fl oz)

## Formula

$$
\text{milliliters} = \text{US fluid ounces} \times 29.5735295625
$$

## Worked examples

### 8 fl oz to mL

- US fluid ounces (fl oz): 8 fl oz
- **Milliliters: 236.5882365 mL**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

### 6 fl oz to mL

- US fluid ounces (fl oz): 6 fl oz
- **Milliliters: 177.441177375 mL**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

### 32 fl oz to mL

- US fluid ounces (fl oz): 32 fl oz
- **Milliliters: 946.352946 mL**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

## Questions

### When would I convert oz to ml?

US fluid ounces are volume measures used on beverage packaging and measuring cups. They are different from ounces of mass and from imperial fluid ounces. Use the labelled US amount as the starting value, and do not infer an ingredient's weight from volume alone.

### How many milliliters are in a US fluid ounce?

One US fluid ounce is exactly 29.5735295625 milliliters. The US fluid ounce is 1/128 of a US gallon, exactly 29.5735295625 mL.

### How do you convert oz to ml?

Multiply the number of US fluid ounces by 29.5735295625. For example, 8 fl oz × 29.5735295625 = 236.588237 mL. To go the other way, divide by 29.5735295625.

### How can I estimate oz to ml without a calculator?

Multiply by 30. That is 1.4% high of the exact factor 29.5735295625, so 8 fl oz comes out as 240 mL instead of 236.5882.

### How accurate is the US fluid ounces to milliliters converter?

Accuracy depends on your inputs and the method's assumptions. Decimal arithmetic uses 50 significant digits, but estimates, numerical methods and source data can be less precise; the displayed rounding does not remove those limits. It is checked against 3 worked examples whose answers come from independent sources; for example, “8 fl oz to mL” is checked against Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions).

### Where does the method come from?

NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B; NIST Handbook 44, Appendix C: General tables of units of measurement; BIPM, The International System of Units (SI Brochure), 9th edition.

## Sources

- [NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44, Appendix C: General tables of units of measurement](https://www.nist.gov/pml/weights-and-measures/publications/nist-handbooks/handbook-44)
- [BIPM, The International System of Units (SI Brochure), 9th edition](https://www.bipm.org/en/publications/si-brochure)