Cups to Fluid Ounces Converter

A U.S. cup is 8 fluid ounces. For dry ingredients, a cup of flour weighs only about 4.4 ounces, so use a weight converter instead.

How to use the Cups to Fluid Ounces Converter

1. Type the number of US cups into the US cups field. Decimals such as 0.5 are fine.
2. Read the answer in US fluid ounces – it updates as you type, with no button to press.
3. To convert the other way, type into US fluid ounces and the US cups are recalculated.
4. Press Copy results to copy both values with the page title, or Copy link to share this exact conversion.

This page converts only US cup ⇄ US fl oz. Need a different unit? Use the general volume converter, where you can choose any “from” and “to” unit.

How it works

Both units measure volume, so they are always in the same ratio: one US cup equals 8 US fluid ounces. The calculator multiplies the number of US cups you type by 8 to give US fluid ounces, and when you type into the US fluid ounces field it divides by the same factor to give US cups. Because the ratio never changes, doubling the US cups always doubles the US fluid ounces. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation).

How to convert US cups to US fluid ounces

1. Write down the value in US cups, for example 1 US cup.
2. Multiply by the conversion factor 8 (because 1 US cup = 8 US fl oz).
3. 1 × 8 = 8 US fl oz.
4. To go back from US fluid ounces to US cups, divide by 8 – or multiply by 0.125.

US cup to US fl oz conversion table

What is a US cup?

The U.S. customary cup is 8 U.S. fluid ounces, about 236.6 mL. Recipes from Australia, Canada and New Zealand often use the 250 mL metric cup instead.

What is a US fluid ounce?

The U.S. fluid ounce is 1/128 of a U.S. gallon, about 29.57 mL. It is a unit of volume: a fluid ounce of water weighs about one ounce, but other liquids do not.

Common mistakes to avoid

Mixing u.s. and uk gallons, pints and fluid ounces, assuming a cup is always 250 ml, and treating volume and weight as interchangeable for anything except water.