US Fluid Ounces to US Cups (fl oz to cup)
1 US fluid ounce equals 0.125 US cups exactly.
How to convert US fluid ounces to US cups
To convert US fluid ounces to US cups, multiply the number of US fluid ounces by 0.125. This factor is exact. To go the other way, multiply US cups by 8.
US cups = US fluid ounces × 0.125
Example: 10 US fluid ounces = 1.25 US cups.
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 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
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
Related conversions
- US cups to US fluid ounces (reverse)
- US fluid ounces to liters
- US fluid ounces to milliliters
- US fluid ounces to US gallons
- US fluid ounces to cubic meters
- US fluid ounces to cubic centimeters
- US fluid ounces to US quarts
- US fluid ounces to US pints
- US fluid ounces to US tablespoons
- US fluid ounces to US teaspoons
- US fluid ounces to metric cups
- US fluid ounces to metric tablespoons
- US fluid ounces to metric teaspoons
- Liters to US cups
- Milliliters to US cups
- US gallons to US cups
- Cubic meters to US cups
- Cubic centimeters to US cups
- US quarts to US cups
- US pints to US cups
- US tablespoons to US cups
- US teaspoons to US cups
- Metric cups to US cups
- Metric tablespoons to US cups
- Metric teaspoons to US cups
See all volume units.