Cups to mL, and which cup it is.

One US cup is 236.588 mL, so to convert cups to milliliters, multiply by 236.588. That makes 2 cups 473.17647 mL, 3 cups 709.76471 mL and 0.5 cup 118.29412 mL. The exact value is 236.5882365 mL, because NIST Handbook 44 (2026), Appendix C (checked 24 Oct 2026) defines a cup as 8 fluid ounces, and a US gallon of 231 cubic inches has 128 of them. Many cooks round to 240 mL, and for a nutrition label that is the rule, so this page shows both.

How to use the converter

1. Type the amount in the US cups (cup) box. Fractions such as 3/4 work.
2. The big result is Milliliters (mL) for the US customary cup.
3. Read the cards. the two cards headed As nutrition label cups (240 mL) in milliliters and As metric cups (250 mL) in milliliters show the same number of cups in the other two sizes.
4. Press S to swap the boxes and convert mL back to cups.
5. Click a row in Common values to load it. Copy result and Copy link keep your answer.

The three cups

21 CFR 101.9(b)(5)(viii) says that for nutrition labeling a cup means 240 mL, a tablespoon 15 mL and a teaspoon 5 mL (checked 24 Oct 2026). No official page was read for the 250 mL cup, so it is listed as common recipe practice. The 250 mL cup is 5.7 percent bigger than the customary one.

Worked examples

• 1 cup of water. 236.6 mL for a US cup, or 240 mL on a label.
• 2 cups of milk. 2 × 236.588 = 473.2 mL.
• 3/4 cup of oil. 0.75 × 236.588 = 177.4 mL.
• 1 1/2 cups of stock. 354.9 mL. Type 1 1/2 and the tool reads it.
• 4 cups. 946.4 mL, which is 0.946 L and a little less than a liter, since a liter is 4.227 cups.
• From mL back. 500 mL ÷ 236.588 = 2.113 cups. Swap the boxes and type 500.

Which one should I use?

If the recipe comes from the US and gives cups, use 236.588 mL, or 240 mL if you want an easy number and the dish is forgiving. Soup, stew and rice are forgiving. Cakes, bread and sauces that set are less so, and there the grams in the recipe are the better guide. Some recipes written outside the US use a 250 mL cup. When a recipe lists mL next to cups, follow the mL.

Measuring jugs and the 1 cup mark

A measuring jug may show cups, mL or both, and its cup line may follow any of the three sizes above, so read its scale. Fill to the line at eye level on a flat surface. The meniscus, the little curve in the liquid, should sit on the line.

Fluid ounces and tablespoons in a cup

Mistakes to avoid

The first is treating mL as grams for anything but water. A cup of flour is about 125 g and a cup of honey 339 g, from USDA household weights used in grams to cups. The second is mixing cup sizes in one recipe. The third is using a coffee cup or a mug, which are not measures.

See also mL to cups, liters to cups, cups to ounces and cups to tablespoons.