Oz to Cups Converter: Fluid Ounces to US Cups

Oz to Cups

oz to Cups Converter

Convert fluid ounces to cups and back

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A US fluid ounce (fl oz) measures volume, and a US cup is a standard kitchen measurement equal to 8 fluid ounces.

Note: this converts fluid ounces (volume) to cups — not weight ounces, which vary by ingredient density (a cup of flour weighs less than a cup of water).

Fluid Ounces (fl oz)

Cups

🍳 Your Result

Converted Value

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Fluid Ounces

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Cups

Calculation

A recipe calling for fluid ounces but your measuring cup only marked in cups, or vice versa, this converter handles the switch instantly using the exact US definition of a cup.

How to use this oz to cups converter

Enter a value in the Fluid Ounces (fl oz) field to see the equivalent in cups.
Or enter a value in the Cups field to see the equivalent in fluid ounces, either field updates the other automatically.

What this converter does

A US fluid ounce measures volume, and a US cup is a standard kitchen measurement defined as exactly 8 fluid ounces. This converter applies that exact relationship in either direction.

1 US cup = 8 US fluid ounces (fl oz), exact by definition

Fluid ounces vs weight ounces: an important distinction

This converter handles fluid ounces (a volume measurement), not weight ounces, which is a completely different unit despite sharing the same name. A cup of flour and a cup of water occupy the identical volume but weigh very different amounts, because flour is far less dense than water. If you’re working from a recipe that specifies weight ounces of a dry ingredient, this fluid-ounce-to-cups conversion is not the right tool, you’d need the ingredient’s density to convert weight to volume accurately.

Frequently asked questions

How many fluid ounces are in a cup?

Exactly 8 US fluid ounces make up 1 US cup, by definition.

Does this work for weight ounces too, like a cup of flour?

No, this converts fluid ounces (volume), not weight ounces. A cup of flour and a cup of water are the same volume but very different weights, since dry ingredients vary in density. Use a weight-based conversion for dry ingredient ounces instead.