How to convert ounces to cups
A US cup holds 8 fluid ounces, so cups = fl oz ÷ 8. For example, 16 fl oz ÷ 8 = 2 cups. This is for liquid (fluid ounce) measures; dry ingredients measured in weight ounces convert differently.
In US customary measure one cup is 8 fluid ounces, which is 236.6 mL. That chain also gives the rest of the kitchen ladder: 2 cups make a pint (16 fl oz), 4 cups make a quart (32 fl oz) and 16 cups make a gallon (128 fl oz). Everything scales by 8, so the division never needs a lookup table.
Common conversions: 4 fl oz is 0.5 cup, 6 fl oz is 0.75 cup, 12 fl oz — a standard soda can — is 1.5 cups, 20 fl oz is 2.5 cups and 64 fl oz is 8 cups. A US nutrition label uses a slightly different "legal cup" of 240 mL, which is why a carton marked as 8 servings of 1 cup may not exactly match a measuring jug.
How to use this calculator
Enter the number of fluid ounces to see the equivalent in US cups. For grams of an ingredient per tablespoon, see the tbsp to grams calculator.
The trap is the word ounce. A fluid ounce measures volume, a weight ounce measures mass, and they only line up for water. Eight fluid ounces of water weighs about 8.3 oz, but 8 fluid ounces of flour weighs closer to 4.4 oz — so a recipe calling for "8 oz of flour" almost certainly means weight, and pouring a cupful would leave you nearly half short.
Cup sizes also differ by country. A US cup is 236.6 mL, a metric cup used in Australia and New Zealand is 250 mL, and a UK imperial fluid ounce is 28.41 mL rather than the US 29.57 mL. Follow the origin of the recipe rather than the jug in your drawer, or sidestep the problem by weighing: the oz to ml calculator gives millilitres directly, and the quarts to cups calculator handles larger batches.
Frequently asked questions
- How many cups is 16 oz?
- 2 cups, since a US cup is 8 fluid ounces.
- How many ounces in a cup?
- 8 fluid ounces in one US cup.
- Is this for liquid or dry ounces?
- Fluid (liquid) ounces. Dry ingredients are usually measured by weight, which converts differently.
- How many cups is 8 oz?
- 1 cup.
- Is a US cup the same as a UK or metric cup?
- No. A US cup is 236.6 mL, while the metric cup used in Australia and New Zealand is 250 mL — about 6% larger. Using the wrong one is minor in a soup but can noticeably change a cake or a bread dough.