# US cups to milliliters converter

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

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

A recipe written in US cups may need conversion for a graduated jug or a set of measuring spoons. Fractions such as a quarter or three quarters of a cup are valid inputs. This is a US customary cup; a metric cup uses a different capacity.

One US cup is exactly 236.5882365 milliliters, so 1 cup is 236.588237 mL. To convert cups to ml, multiply by 236.5882365; to convert back, multiply by 0.0042267528.

The US customary cup is 8 US fluid ounces, exactly 236.5882365 mL. Because both units are defined exactly, the factor above is exact and the results here carry no conversion error.

## Inputs

- **US cups (cup)**

## Results

- Milliliters (mL) — main result
- Conversion
- 1 mL in US cups (cup)

## Formula

$$
\text{milliliters} = \text{US cups} \times 236.5882365
$$

## Worked examples

### 1 cup to mL

- US cups (cup): 1 cup
- **Milliliters: 236.5882365 mL**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

### 0.67 cup to mL

- US cups (cup): 0.67 cup
- **Milliliters: 158.514118455 mL**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

### 3 cup to mL

- US cups (cup): 3 cup
- **Milliliters: 709.7647095 mL**
- Checked against: Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions)

## Questions

### When would I convert cups to ml?

A recipe written in US cups may need conversion for a graduated jug or a set of measuring spoons. Fractions such as a quarter or three quarters of a cup are valid inputs. This is a US customary cup; a metric cup uses a different capacity.

### How many milliliters are in a US cup?

One US cup is exactly 236.5882365 milliliters. The US customary cup is 8 US fluid ounces, exactly 236.5882365 mL.

### How do you convert cups to ml?

Multiply the number of US cups by 236.5882365. For example, 1 cup × 236.5882365 = 236.588237 mL. To go the other way, divide by 236.5882365.

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

Multiply by 240. That is 1.4% high of the exact factor 236.5882365, so 1 cup comes out as 240 mL instead of 236.5882.

### Is a cup 240 mL or 236.6 mL?

Both are in use. The US customary cup in recipes is 236.588 mL. US nutrition labels use a rounded "legal cup" of 240 mL (21 CFR 101.9), and the metric cup used in Australia, New Zealand and Canada is 250 mL.

### How accurate is the US cups 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, “1 cup 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)