Liters to US cups converter

Liter volumes commonly describe bottles, tanks and liquid purchases. A fractional liter can be useful when comparing container capacities or adapting a recipe. If the destination uses gallons or cups, check the regional definition before deciding how many containers to buy.

One litre is about 4.2267528377 US cups. The US customary cup is 8 US fluid ounces, exactly 236.5882365 mL.

Multiply the number of liters by 4.2267528377. For example, 1 L × 4.2267528377 = 4.226753 cup. To go the other way, divide by 4.2267528377.

Multiply by 4.2. That is 0.6% low of the exact factor 4.2267528377, so 1 L comes out as 4.2 cup instead of 4.2268.

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, “1 L 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.