Oz to Cup Converter

Easily convert ounces to cups and cups to ounces with our free printable chart. Whether you’re converting 64 oz to cups, checking 16 oz in cups, or converting a quarter cup to ounces, get the answer quickly.


The short answer

How many ounces are in a cup?

For liquids, 1 cup equals exactly 8 fluid ounces. That ratio stays the same whether you’re measuring water, milk, or oil because both are units of volume. So, 1 oz to cup is 1/8 cup, while 2 cups is 16 oz, 4 cups is 32 oz, and 8 cups is 64 oz.

The confusion usually starts when you’re converting ingredients by weight. A cup of flour doesn’t weigh the same as a cup of water because flour is much less dense. So, how many oz in a cup of flour is about 4.4 oz, while how many oz in a cup of water is about 8.3 oz. That’s why this converter includes separate options for liquid and ingredient conversions rather than relying on one fixed formula.


Common oz to cup conversions

Fluid ouncesCupsAlso known as
1 oz1/8 cup2 tablespoons
2 oz1/4 cupquarter cup
4 oz1/2 cuphalf cup
6 oz3/4 cup
8 oz1 cup
16 oz2 cups1 pint
32 oz4 cups1 quart
64 oz8 cups1/2 gallon
All values based on the US customary cup (8 fl oz). The converter above also supports Metric and UK cup sizes, which shift these numbers slightly.
Where this gets confusing

Why “oz to cup” isn’t always the same math

A US recipe calling for “1 cup” almost always means volume, not weight — but ounces are used for both, and that’s the source of most conversion mix-ups. If a recipe says 8 oz of butter, that’s a weight measurement, and 8 oz of butter is roughly 1 cup, not because of the fluid-ounce ratio, but because butter happens to weigh close to that much per cup. Sugar doesn’t work out the same way — 1 cup of granulated sugar is closer to 7 oz by weight, and a cup of all-purpose flour is closer to 4.4 oz.

The Ingredient tab handles this correctly: pick flour, sugar, butter, honey, rice, or one of the other common ingredients, and it converts using that ingredient’s actual density instead of the fixed 8-oz-per-cup liquid ratio. That’s the difference between a converter that’s technically right for water and one that’s actually useful in a kitchen. If your recipe lists grams instead of ounces, our cups to grams converter handles that same ingredient-by-ingredient conversion in metric.

Quick rule If you’re measuring something you’d pour — water, milk, oil, juice — use Fluid Ounces mode. If you’re measuring something you’d scoop or weigh — flour, sugar, butter — use Ingredient mode.

Working in smaller amounts than a cup? A tbsp to cups converter is the faster path once you’re down to a few spoonfuls, and if your recipe drops all the way to teaspoons, our tsp to tbsp converter covers that last step.


What the converter does

🥛 Fluid ounce conversions Enter any amount — 64 oz, 32 oz, 16 oz, 6 oz, or a custom number — and get an instant cup equivalent, in either direction.
🌍 US, Metric & UK cup sizes Switch cup size and every result updates, since a US cup, metric cup, and UK cup aren’t quite the same volume.
🧈 Ingredient-specific weight Get the real oz-per-cup value for flour, sugar, butter, honey, oats, rice, and more — not just water’s ratio.
📋 Quick reference & printable chart Tap a fraction card (1/8 to 1 cup) to load it instantly, or print the full chart for the kitchen.

Frequently asked questions

How many ounces are in a cup?

There are 8 fluid ounces in 1 US cup. This is a fixed volume ratio that applies to any liquid. It’s different from weight ounces, where the amount per cup depends on the ingredient — for example, 1 cup of flour weighs about 4.4 oz, not 8 oz.

How many cups is 64 oz?

64 fluid ounces equals 8 cups. This is exactly a half-gallon, since 1 gallon is 128 fl oz.

How many cups is 32 oz?

32 fl oz equals 4 cups, which is also 1 quart.

How many cups is 16 oz?

16 fl oz equals 2 cups, or 1 US pint.

How many cups is 6 oz?

6 fluid ounces equals 0.75 cup, or 3/4 cup.

What is a quarter cup in ounces?

A quarter cup (1/4 cup) equals 2 fluid ounces. For weight-based ingredients like flour or sugar, the ounce equivalent will differ — use the Ingredient tab on the converter for those.

Is 1 oz equal to 1/8 cup?

Yes, for fluid ounces: 1 fl oz equals 1/8 cup, since a cup holds 8 fl oz. This applies to liquid measurements only, not to ingredients measured by weight.


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