# Milliliters to US fluid ounces converter

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

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

Milliliter markings appear on measuring jugs and small containers. Read the volume scale, not a mass label, and identify the destination's cup or fluid-ounce convention. Kitchen measures are often approximate, so the vessel's graduations may limit the useful precision.

One millilitre is about 0.0338140227 US fluid ounces, so 250 mL is 8.453506 fl oz. To convert ml to oz, multiply by 0.0338140227; to convert back, multiply by 29.5735295625.

The litre is exactly one cubic decimetre, so 1 L is 1,000 mL and 1 mL is 1 cm³. The factor has no exact decimal form, so results are computed with 50 significant digits and rounded only for display.

## Inputs

- **Milliliters (mL)**

## Results

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

## Formula

$$
\text{US fluid ounces} = \text{milliliters} \times 0.0338140227018
$$

## Worked examples

### 250 mL to fl oz

- Milliliters (mL): 250 mL
- **US fluid ounces: 8.4535056755 fl oz**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

### 50 mL to fl oz

- Milliliters (mL): 50 mL
- **US fluid ounces: 1.6907011351 fl oz**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

### 750 mL to fl oz

- Milliliters (mL): 750 mL
- **US fluid ounces: 25.3605170264 fl oz**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

## Questions

### When would I convert ml to oz?

Milliliter markings appear on measuring jugs and small containers. Read the volume scale, not a mass label, and identify the destination's cup or fluid-ounce convention. Kitchen measures are often approximate, so the vessel's graduations may limit the useful precision.

### How many US fluid ounces are in a millilitre?

One millilitre is about 0.0338140227 US fluid ounces. The litre is exactly one cubic decimetre, so 1 L is 1,000 mL and 1 mL is 1 cm³.

### How do you convert ml to oz?

Multiply the number of milliliters by 0.0338140227. For example, 250 mL × 0.0338140227 = 8.453506 fl oz. To go the other way, divide by 0.0338140227.

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

Multiply by 0.034. That is 0.6% high of the exact factor 0.0338140227, so 250 mL comes out as 8.5 fl oz instead of 8.4535.

### How accurate is the milliliters to US fluid ounces 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, “250 mL to fl oz” 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)