Ounces to Cups Converter

1 US customary cup equals exactly 8 US fluid ounces, which works out to 16 customary tablespoons, 48 customary teaspoons, or approximately 236.59 mL. A US legal cup used for nutrition labeling is exactly 240 mL, so check which cup standard your source uses.

No. A US customary cup is approximately 236.59 mL (exactly 8 US fluid ounces), while a historical UK imperial cup is approximately 284.13 mL (10 imperial fluid ounces). The UK cup is about 20 percent larger. Many British recipes today use an exact 250 mL metric cup instead. Check which system a recipe uses before scaling.

Recipes are written in halves, quarters, thirds, and eighths: 1/8 cup (2 tbsp), 1/4 cup (4 tbsp), 1/3 cup (5 tbsp + 1 tsp), 1/2 cup (8 tbsp), 2/3 cup (10 tbsp + 2 tsp), 3/4 cup (12 tbsp), and 1 cup (16 tbsp). Anything below 1/8 cup is usually written in tablespoons, and anything below 1 tablespoon is written in teaspoons. The converter snaps the cups output to the nearest of these standard fractions so the recipe-friendly line matches how recipes are actually written.

A fluid ounce measures volume (about 29.57 mL in the US), while a weight ounce measures mass (28.35 g). For water at room temperature the two happen to be roughly equal: 1 US fl oz of water weighs about 1.04 oz by weight, close enough for casual cooking. For other liquids the relationship breaks. 1 fl oz of honey weighs about 1.5 oz (because honey is dense, around 1.42 g/mL); 1 fl oz of olive oil weighs about 0.95 oz (because oil is lighter, around 0.91 g/mL). Always check whether a recipe asks for fluid ounces (volume) or ounces (weight).

Multiply every ingredient by the same ratio. To double a recipe, multiply each amount by 2; to halve it, multiply by 0.5. If a recipe calls for 3/4 cup of milk and you want 1.5 times the batch, that becomes 9/8 cup, which the converter rounds to 1 1/8 cup (or 9 fl oz, or 18 tbsp). Keep an eye on cooking times, baking pan sizes, and leavening when you scale beyond 2x: baking soda, baking powder, and salt usually scale linearly, but bake times grow with pan area, not volume.