Fluid ounces to cups
One fl oz equals 0.125 cup. Type any number and the answer appears as you type — the maths happens in your browser.
Result
The same value in every unit
| Unit | Value |
|---|
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Common values
| fluid ounces | cups |
|---|---|
| 1 fl oz | 0.125 cup |
| 2 fl oz | 0.25 cup |
| 3 fl oz | 0.375 cup |
| 5 fl oz | 0.625 cup |
| 10 fl oz | 1.25 cup |
| 15 fl oz | 1.875 cup |
| 20 fl oz | 2.5 cup |
| 25 fl oz | 3.125 cup |
| 50 fl oz | 6.25 cup |
| 100 fl oz | 12.5 cup |
| 500 fl oz | 62.5 cup |
| 1000 fl oz | 125 cup |
How to use
- Enter the number of fluid ounces in the field.
- The result in cups updates on every keystroke.
- Use the table below for the values people look up most often.
Formula and reverse conversion
The formula
To convert by hand: cup = fl oz ÷ 8. Going back the other way, one cup is 8 fl oz.
Where the odd number comes from
The factor is not a round number because the imperial units are defined through the metric ones by international agreement: an inch is exactly 25.4 mm and a pound is exactly 0.45359237 kg. Everything else follows from those definitions.
cup = fl oz ÷ 8
Frequently asked questions
How many cups are in one fluid ounces?
One fl oz is 0.125 cup.
How do I convert fluid ounces to cups?
Multiply by the factor: cup = fl oz ÷ 8.
Is the result exact?
The factors are the exact legal definitions, and up to ten significant digits are kept in the answer. Rounding happens only in the display.
How do I convert cups back to fluid ounces?
One cup is 8 fl oz — or open the reverse page linked below.