Unit Converters

Cups to Fluid Ounces Converter

Convert cups to fluid ounces, with five cup standards to choose from. The default US customary cup is exactly 8 fl oz.

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Converted amount
8 fl oz

1 cup · US customary

This cup holds
8 fl oz
1 cup equals
8 fl oz
Conversion factors are exact; rounding may affect the final digit.
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How it's calculated

fl oz = cups × 8

US: 1 cup = 8 fl oz (selectable standard). Reverse: cups = fl oz ÷ 8.

Common values

Cups (US)Fluid Ounces (US)
0.252
0.54
18
216
432

Common questions

How many fluid ounces are in a cup?

Eight fluid ounces in a US customary cup. Other standards differ slightly, which is why the converter lets you switch.

Why are there five cup standards?

US customary, US legal, metric, UK imperial, and the Japanese 200 mL go all define a cup differently, so recipes from different regions vary.