Convert cups to fluid ounces

1 cup equals 8 fluid ounces. Type any number below — the other side updates instantly.

By Numerly · Updated June 14, 2026

cups

cup

fluid ounces

fl oz

Type to convert

Cups to fluid ounces — quick reference

cups	fluid ounces
0.25 cup	2 fl oz
0.5 cup	4 fl oz
1 cup	8 fl oz
1.5 cup	12 fl oz
2 cup	16 fl oz
3 cup	24 fl oz
4 cup	32 fl oz
5 cup	40 fl oz
8 cup	64 fl oz
10 cup	80 fl oz

Convert a specific value

The most-searched exact cups-to-fluid ounces amounts, each with its own page.

How to convert

Multiply the number of cups by 8 to get fluid ounces. To go the other way, multiply fluid ounces by 0.125 to get cups. The conversion factor is fixed and exact, so you can use this on any value.

About these units

Cups

Definition: A US cup is 8 US fluid ounces, or about 236.6 ml. The metric cup is 250 ml exactly.
History: Standardized cooking measures became common in the US in the early 20th century, popularized by Fannie Farmer's Boston Cooking-School Cook Book (1896).
Current use: The cup is the everyday cooking measure in the US, Canada, Australia, and many English-language recipes worldwide.

Fluid ounces

Definition: A US fluid ounce (symbol: fl oz) equals about 29.57 ml. There are 16 fl oz in a US pint and 128 in a US gallon.
History: The US fluid ounce was set by Congress in 1832. The Imperial fluid ounce (used in the UK) is slightly different at about 28.41 ml.
Current use: Used in the US for liquid measurements — beverages, recipes, cosmetics — and shown on most US food and drink labels.

Frequently asked

How many fluid ounces are in 1 cup?: 1 cup = 8 fluid ounces.
How do you convert cups to fluid ounces?: Multiply the number of cups by 8 to get fluid ounces. To go the other way, multiply fluid ounces by 0.125 to get cups. The conversion factor is fixed and exact, so you can use this on any value.
What is 3 cups in fluid ounces?: 3 cups = 24 fluid ounces.
What is 5 cups in fluid ounces?: 5 cups = 40 fluid ounces.
What is 8 cups in fluid ounces?: 8 cups = 64 fluid ounces.