Converting fluid ounces to cups
In the U.S. customary system used in most American recipes, 1 cup equals exactly 8 fluid ounces. This calculator converts between the two using that standard relationship, in either direction.
Fluid ounces measure volume (not weight), so this conversion applies to liquid ingredients like water, milk, or oil. The milliliter equivalent is also shown, using the standard factor of 1 U.S. fluid ounce = 29.5735 mL, for comparison against metric recipes.
This tool is intended for general cooking and educational purposes. Note that some countries define a "cup" slightly differently (for example, the metric cup used in Australia and the UK is 250 mL), so always check your recipe’s origin if precision matters.
Last reviewed August 2026