US Cups to US Fluid Ounces (cup to fl oz)
1 US cup equals 8 US fluid ounces exactly.
How to convert US cups to US fluid ounces
To convert US cups to US fluid ounces, multiply the number of US cups by 8. This factor is exact. To go the other way, multiply US fluid ounces by 0.125.
US fluid ounces = US cups × 8
Example: 10 US cups = 80 US fluid ounces.
Pints, quarts, gallons and fluid ounces differ between the US and the UK. Units are labeled 'US' or 'imperial' to avoid confusion.
About these units
US Cup (cup)
One sixteenth of a US gallon, 236.588 mL (8 US fluid ounces). The standard US recipe cup.
Cups began as household drinking vessels, not scientific units, which is why they remain the messiest measures in the kitchen. The US customary cup was defined by slicing up the gallon: half a pint, or eight US fluid ounces, about 236.6 milliliters. Unlike the larger units, nobody ever fixed it to a physical vessel, so it exists only as a fraction of the gallon.
The customary cup is not the only American cup. For nutrition labels, US regulation defines a cup as exactly 240 milliliters, a rounder figure that sits slightly above the customary size. Packaged foods therefore list a serving in the legal cup while a measuring cup from the hardware store follows the customary definition. The gap is 3.4 milliliters, which hardly matters for soup but can matter in baking. Cup measures also hide the weight of dry ingredients, since a cup of sifted flour and a cup of packed flour differ substantially, which is why much of the world prefers grams.
1 US cup = 0.2365882365 liters (exactly).
Sources: Wikipedia: Cup (unit); NIST SP 811, Appendix B.8: conversion factors for volume; 21 CFR 101.9: nutrition labeling household measures
US Fluid Ounce (fl oz)
One 128th of a US gallon, 29.5735 mL. Not the same as the weight ounce, and about 4% larger than the imperial fluid ounce.
Fluid ounce began as an attempt to link volume to weight: the volume occupied by one ounce of some substance, such as wine in England or water in Scotland. Definitions varied by region and by liquid. When Britain defined its imperial gallon in 1824 as the space of ten pounds of water, the imperial fluid ounce came out so that an ounce of water weighs about one avoirdupois ounce. The US fluid ounce followed a different path and comes from the older wine gallon.
The US fluid ounce is exactly 1/128 of a US gallon, 29.5735295625 milliliters, about 4 percent bigger than the imperial one at 28.4130625 milliliters. American nutrition labels use yet another figure, treating one fluid ounce as 30 milliliters, a convenient rounding for serving sizes. The name is a trap, because a fluid ounce measures space while a weight ounce measures mass. A US fluid ounce of water weighs a bit more than an ounce of weight, while a fluid ounce of honey weighs considerably more.
1 US fluid ounce = 0.02957352956 liters (approximately).
Sources: Wikipedia: Fluid ounce; NIST SP 811, Appendix B.8: conversion factors for volume; 21 CFR 101.9: nutrition labeling household measures
Related conversions
- US fluid ounces to US cups (reverse)
- US cups to liters
- US cups to milliliters
- US cups to US gallons
- US cups to cubic meters
- US cups to cubic centimeters
- US cups to US quarts
- US cups to US pints
- US cups to US tablespoons
- US cups to US teaspoons
- US cups to metric cups
- US cups to metric tablespoons
- US cups to metric teaspoons
- Liters to US fluid ounces
- Milliliters to US fluid ounces
- US gallons to US fluid ounces
- Cubic meters to US fluid ounces
- Cubic centimeters to US fluid ounces
- US quarts to US fluid ounces
- US pints to US fluid ounces
- US tablespoons to US fluid ounces
- US teaspoons to US fluid ounces
- Metric cups to US fluid ounces
- Metric tablespoons to US fluid ounces
- Metric teaspoons to US fluid ounces
See all volume units.