Convert Milliliter to US Cup

One US customary cup holds exactly 236.5882365 mL — approximately 236.6 mL in practice. To convert milliliters to cups, divide by 236.588. A 500 mL bottle of water is about 2.11 US cups; a standard 750 mL wine bottle is just under 3.17 cups. These numbers matter most when adapting a European recipe (which measures liquids in milliliters or liters) for a North American kitchen that works in cups.

The most important gotcha in this conversion is the US legal cup, also called the nutrition-labeling cup. The FDA defines it as exactly 240 mL for food-labeling purposes — about 1.5% larger than the 236.588 mL customary cup. Most nutrition panels on packaged food use the 240 mL cup. A recipe cup measure, however, is the 236.588 mL version. The difference is small — just 3.4 mL — but it accumulates: over eight cups, that is 27 mL off, which can noticeably affect a custard or sauce.

Baking is the context where this conversion is most consequential. Volume measures of flour are notoriously inconsistent (a 'cup' of flour can range from 120 g to 150 g depending on how it is scooped), so professional bakers increasingly use grams. When a metric recipe specifies, say, 240 mL of milk, that is very close to one US cup — but for precision, weighing or using a graduated cylinder beats both.