Milliliters to US cups converter

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 0.0042267528 US cups. The litre is exactly one cubic decimetre, so 1 L is 1,000 mL and 1 mL is 1 cm³.

Multiply the number of milliliters by 0.0042267528. For example, 250 mL × 0.0042267528 = 1.056688 cup. To go the other way, divide by 0.0042267528.

Multiply by 0.0042. That is 0.6% low of the exact factor 0.0042267528, so 250 mL comes out as 1.05 cup instead of 1.0567.

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.

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 cup” is checked against Exact-fraction computation from the legal unit definitions (scripts/gen-pairs.py, Python fractions).

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.