Oz to Cups: Fluid and Dry Ounces Converter
Fluid ounces and dry ounces handled separately, because they aren't the same measurement.
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Fluid ounces aren't dry ounces. A cup holds 8 fluid ounces of any liquid, always. But 8 ounces of flour by weight fills nearly two cups, because flour is far less dense than water. If your recipe says "8 oz flour" it almost certainly means weight, so switch the control above to dry.
The formulas
1 US cup = 236.5882365 mL (exact)
1 US fluid ounce = 29.5735295625 mL (exact)
These are exact definitional values. Note that the US customary cup used here differs from the US legal cup of 240 mL used on nutrition labels, and from the imperial cup of roughly 284 mL. Definitions per the NIST Guide to the SI, Appendix B.
Fluid ounce conversion table
| Fluid ounces | Cups | Milliliters |
|---|---|---|
| 1 fl oz | 0.125 | 29.6 |
| 2 fl oz | 0.25 | 59.1 |
| 4 fl oz | 0.5 | 118.3 |
| 6 fl oz | 0.75 | 177.4 |
| 8 fl oz | 1 | 236.6 |
| 10 fl oz | 1.25 | 295.7 |
| 12 fl oz | 1.5 | 354.9 |
| 16 fl oz | 2 | 473.2 |
| 20 fl oz | 2.5 | 591.5 |
| 24 fl oz | 3 | 709.8 |
| 32 fl oz | 4 | 946.4 |
Which cup is on your shelf
A liquid measuring cup, usually glass with a spout and graduations up the side, is for fluid ounces. Fill it to the line and read at eye level. A dry measuring cup, usually metal and filled flush to the rim, is for volume measures of dry ingredients, not for weight.
If a recipe gives dry ingredients in ounces rather than cups, it wants a scale. Converting to cups introduces the same variability that makes flour measurement inconsistent in the first place.
Common questions
Does 8 oz make 1 cup?
For liquids, yes. One US cup is 8 US fluid ounces exactly. For dry ingredients measured by weight it depends entirely on the ingredient: 8 ounces of flour is closer to 1.9 cups.
Is 16 oz equal to 1 cup?
No. 16 US fluid ounces is 2 cups. 16 ounces is 1 pound by weight, which is a different measurement.
What is the difference between fluid ounces and dry ounces?
A fluid ounce measures volume, how much space something takes up. A dry ounce measures weight. They share a name but aren't interchangeable, which is the single most common error in recipe conversion.
How many ounces is 1 cup?
One US cup is 8 US fluid ounces, 236.588 milliliters, 16 tablespoons or 48 teaspoons.
Related converters and guides
Sources
- NIST Guide to the SI, Appendix B: Conversion Factors. National Institute of Standards and Technology. Source for every conversion factor on this page. NIST prints exact factors in boldface and rounds the rest to the digits shown, which is the convention this site follows.