In US recipes, a cup is 8 fluid ounces
That single number covers almost every US recipe: 4 fl oz is half a cup, 2 fl oz is a quarter. Use the standard selector on the calculator only when a recipe is written for metric (250 mL) or UK (284 mL) cups.
Fluid ounces to cups
| Fluid ounces | Cups | Also |
|---|---|---|
| 2 fl oz | ¼ cup | 4 tbsp |
| 4 fl oz | ½ cup | 8 tbsp |
| 6 fl oz | ¾ cup | 12 tbsp |
| 8 fl oz | 1 cup | 236.6 mL |
| 16 fl oz | 2 cups | 1 US pint |
| 32 fl oz | 4 cups | 1 US quart |
The weight trap: a cup of water is 8 oz on a scale, but a cup of flour is about 4.25 oz and a cup of sugar about 7 oz. Convert by volume for liquids, weigh by grams for baking accuracy.
Cup standards, if the recipe isn't American
| Standard | Holds | In mL |
|---|---|---|
| US customary | 8 fl oz | 236.6 mL |
| US legal (labels) | 8.12 fl oz | 240 mL |
| Metric | 8.45 fl oz | 250 mL |
| UK / Commonwealth | 10 imp fl oz | 284 mL |
Common questions
How many ounces are in a cup?
A US customary cup is 8 fluid ounces. So half a cup is 4 fl oz and a quarter cup is 2 fl oz. This is for liquid volume, not dry weight.
Is a dry cup the same as a fluid cup?
The cup volume is the same, but "8 oz" on a scale is a weight and does not fill one cup for most dry foods. A cup of flour weighs about 4.25 oz, while a cup of water weighs 8 oz.
Are US and metric cups the same?
Close, not identical. A US customary cup is 236.6 mL, a US legal cup (nutrition labels) is 240 mL, a metric cup is 250 mL, and a UK cup is 284 mL. For most recipes the difference is small.
