The US cup, unit of volume
The US cup holds exactly 236.5882365 milliliters, that is eight US fluid ounces or a sixteenth of a US gallon. It is the cup of American recipes, and its value is not round because it is defined from the gallon and not from the liter.
The United States has two cups and they differ by one and a half per cent. The one above is the customary cup of the kitchen; the cup used on food labels holds exactly 240 milliliters, fixed by the Food and Drug Administration in the rules that carry out the Nutrition Labeling and Education Act of 1990. A serving of one cup on a carton is therefore not the cup in the recipe, and neither is the metric cup of 250 milliliters used in Australia and New Zealand, nor the Japanese cup of 200.
The US cup in other units
| 1 cup | 0.000236588 m³ |
| 1 cup | 0.236588 l |
| 1 cup | 23.6588 cl |
| 1 cup | 236.588 ml |
| 1 cup | 0.0625 gal |
| 1 cup | 0.0520421 gal UK |
| 1 cup | 0.5 pt |
| 1 cup | 8 fl oz |
| 1 cup | 8.32674 fl oz UK |
| 1 cup | 0.25 qt |
| 1 cup | 0.208169 qt UK |
| 1 cup | 0.416337 pt UK |
| 1 cup | 0.946353 cup metric |
| 1 cup | 1.18294 cup JP |
| 1 cup | 16 tbsp |
| 1 cup | 15.7725 tbsp metric |
| 1 cup | 11.8294 tbsp AU |
| 1 cup | 48 tsp |
| 1 cup | 47.3176 tsp metric |
| 1 cup | 2.36588 dl |
| 1 cup | 0.0014881 bbl |
| 1 cup | 0.131153 sho |
| 1 cup | 1.31153 go |
Frequently asked questions
How many milliliters are in a US cup?
236.5882365 exactly, which rounds to 236.59. The figure of 240 that circulates is real but belongs to nutrition labels, not to recipes: the two coexist in the same country and the same kitchen.
Is an American cup the same as a metric cup?
No, and the gap is 5.7 per cent. The metric cup holds 250 milliliters, the American one 236.59. On a cup of plain flour, about 125 grams, that difference is roughly seven grams, which a cake tolerates and a bread dough does not.
Why is the value not a round number?
Because the cup was never defined from the liter. It is a sixteenth of a US gallon, itself fixed at 3.785411784 liters exactly since the inch went metric in 1959. Every US kitchen measure descends from that gallon, which is why they all fall on long decimals.