How to convert US cups to US fluid ounces
One US cup equals 8 US fluid ounces, so multiply the number of US cups by 8:
US fl oz = cup × 8
cup = US fl oz ÷ 8 (1 US fl oz = 0.125 cup)
Example: 0.25 cup → 0.25 × 8 = 2 US fl oz.
Going the other way, divide by 8, or multiply by 0.125; the US fluid ounces to US cups converter does it for you.
Everyday values
| US cups | US fluid ounces | For example |
|---|---|---|
| 0.25 cup | 2 US fl oz | 1/4 cup |
| 0.5 cup | 4 US fl oz | 1/2 cup |
| 1 cup | 8 US fl oz | one cup |
| 2 cup | 16 US fl oz | a pint |
| 4 cup | 32 US fl oz | a quart |
When you need this conversion
Multiply cups by 8 to get US fluid ounces. Drink sizes and baby bottles are usually labelled in fluid ounces, recipes in cups.
US cup to US fluid ounce conversion table
| cup | US fl oz | cup | US fl oz |
|---|---|---|---|
| 0.25 cup | 2 US fl oz | 2.75 cup | 22 US fl oz |
| 0.5 cup | 4 US fl oz | 3 cup | 24 US fl oz |
| 0.75 cup | 6 US fl oz | 3.25 cup | 26 US fl oz |
| 1 cup | 8 US fl oz | 3.5 cup | 28 US fl oz |
| 1.25 cup | 10 US fl oz | 3.75 cup | 30 US fl oz |
| 1.5 cup | 12 US fl oz | 4 cup | 32 US fl oz |
| 1.75 cup | 14 US fl oz | 4.25 cup | 34 US fl oz |
| 2 cup | 16 US fl oz | 4.5 cup | 36 US fl oz |
| 2.25 cup | 18 US fl oz | 4.75 cup | 38 US fl oz |
| 2.5 cup | 20 US fl oz | 5 cup | 40 US fl oz |
About the units
- US cup (cup): 8 US fluid ounces, about 236.6 millilitres (legal nutrition-label cup: 240 ml).
- US fluid ounce (US fl oz): 1/128 of a US gallon, about 29.57 millilitres.
Both are units of volume. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many US fluid ounces are in one US cup?
One US cup is 8 US fluid ounces. One US fluid ounce is 0.125 US cups.
How do I convert US cups to US fluid ounces?
Multiply the value in US cups by 8. To go back, divide by 8.
What is 0.25 cup in US fluid ounces?
0.25 cup = 2 US fl oz.
What is 0.5 cup in US fluid ounces?
0.5 cup = 4 US fl oz.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.