Convert US fluid ounces to US cups
1 US fluid ounce is 0.13 cup. One US fluid ounce is exactly 0.125 US cups.
One US fluid ounce is 0.125 US cups. To convert US fluid ounces to US cups, multiply by 0.125; to go the other way, divide by 0.125 or multiply by 8. The factor is exact rather than rounded: it follows from NIST Handbook 130. Exactly one 128th of a US gallon, which makes it 29.5735295625 ml exactly.
Factor checked against the defining standard · How we check
- US fluid ounces × 0.125
1 * 0.1250.125 cup
1 US fluid ounce in every volume unit
| Unit | Value | Exact factor |
|---|---|---|
| US teaspoons | 6 tsp | × 6 |
| US tablespoons | 2 tbsp | × 2 |
| US fluid ounces (as entered) | 1 fl oz | — |
| US cups | 0.125 cup | × 0.125 |
| US pints | 0.0625 pt | × 0.0625 |
| US quarts | 0.03125 qt | × 0.03125 |
| US gallons | 0.0078125 gal | × 0.0078125 |
| milliliters | 29.57352956 ml | × 29.5735295625 |
| liters | 0.02957352956 L | × 0.0295735295625 |
| imperial gallons | 0.006505267067 gal (UK) | × 0.00650526706741 |
| imperial quarts | 0.02602106827 qt (UK) | × 0.0260210682697 |
| imperial pints | 0.05204213654 pt (UK) | × 0.0520421365393 |
| imperial fluid ounces | 1.040842731 fl oz (UK) | × 1.04084273079 |
| imperial gills | 0.2081685462 gi (UK) | × 0.208168546157 |
| cubic millimetres | 29,573.52956 mm³ | × 29,573.5295625 |
| cubic centimetres | 29.57352956 cm³ | × 29.5735295625 |
| cubic inches | 1.8046875 in³ | × 1.8046875 |
| cubic feet | 0.00104437934 ft³ | × 0.00104437934028 |
| cubic yards | 0.00003868071631 yd³ | × 0.0000386807163066 |
| cubic metres | 0.00002957352956 m³ | × 0.0000295735295625 |
Factors are entered by hand from NIST Handbook 130 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert US fluid ounces to US cups? The converter and the working
- 1.Take the measurement in US fluid ounces.
- 2.Multiply by 0.125 — that is how many US cups fit in one US fluid ounce.
- 3.To go back the other way, divide by 0.125, or multiply by 8.
Worked example: 25 US fluid ounces to US cups
- Formula
- fl oz × 0.125 = cup
- Arithmetic
- 25 × 0.125 = 3.13 cup
- Answer
- 25 fl oz = 3.13 cup
The factor is exact, so this figure is exact too — only the display is rounded.
US fluid ounces to US cups conversion table
| US fluid ounces | US cups |
|---|---|
| 1 fl oz | 0.13 cup |
| 2 fl oz | 0.25 cup |
| 3 fl oz | 0.38 cup |
| 4 fl oz | 0.5 cup |
| 5 fl oz | 0.63 cup |
| 6 fl oz | 0.75 cup |
| 7 fl oz | 0.88 cup |
| 8 fl oz | 1 cup |
| 9 fl oz | 1.13 cup |
| 10 fl oz | 1.25 cup |
| 12 fl oz | 1.5 cup |
| 15 fl oz | 1.88 cup |
| 20 fl oz | 2.5 cup |
| 25 fl oz | 3.13 cup |
| 50 fl oz | 6.25 cup |
| 100 fl oz | 12.5 cup |
| 200 fl oz | 25 cup |
| 300 fl oz | 37.5 cup |
| 500 fl oz | 62.5 cup |
| 1000 fl oz | 125 cup |
| 2000 fl oz | 250 cup |
| 5000 fl oz | 625 cup |
| 10000 fl oz | 1,250 cup |
What is a US fluid ounce?
Exactly one 128th of a US gallon, which makes it 29.5735295625 ml exactly. The imperial fluid ounce is a different unit at exactly 28.4130625 ml, so a UK recipe calling for 10 fl oz means 284 ml and a US one means 296 ml. It is also a volume, not a weight: an ounce of flour is not a fluid ounce of flour.
What is a US cup?
Eight US fluid ounces, about 236.6 ml. The "legal" cup on nutrition labels is a rounded 240 ml.
How many US cups are in a US fluid ounce?
One US fluid ounce is 0.125 US cups, exactly. Going the other way, one US cup is 8 US fluid ounces. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every volume unit here
The whole group — 20 units with their symbols and the size of each one in liters — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a US fluid ounce.
Cite this page
- APA
- Rule Calculator. (2026). Convert US fluid ounces to US cups. Rule Calculator. https://rulecalculators.com/convert/fluid-ounce-to-cup
- MLA
- "Convert US fluid ounces to US cups." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/fluid-ounce-to-cup.
- Chicago
- Rule Calculator. "Convert US fluid ounces to US cups." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/fluid-ounce-to-cup.
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Questions people actually ask
- How many US cups are in a US fluid ounce?
- 0.125. Eight US fluid ounces, about 236.6 ml. The "legal" cup on nutrition labels is a rounded 240 ml.
- How do I convert US cups back to US fluid ounces?
- Divide by 0.125, or multiply by 8 — they are the same operation.
Other volume conversions
US cups to US fluid ounces — the same conversion the other way.