Ounces to Cups Converter
One US cup holds exactly 8 US fluid ounces — but ounces on a kitchen scale are a different unit. Convert in either direction, then see how weight ounces compare below.
Example: with Amount 8 · Direction Fluid ounces → cups → Converted amount: 1.00 cups.
Computed by the calculator below using its default values. Change any input to see your own numbers.
📏 Angled measuring cups make ounces easy
Check it outHow many ounces are in a cup?
1 US cup = 8 US fluid ounces, exactly. So ½ cup is 4 fl oz, ¼ cup is 2 fl oz, 2 cups (1 pint) are 16 fl oz, and 4 cups (1 quart) are 32 fl oz. Going the other way, divide by 8: 12 fl oz of broth is 12 ÷ 8 = 1.5 cups.
The catch is that fluid ounces measure volume, while the ounces on a scale measure weight — and they only line up for water-like liquids. A cup of water weighs about 8.3 oz, so the shortcut works there. But a cup of all-purpose flour weighs only about 4.2 oz (120 g), and a cup of sugar about 7.1 oz. Flip it around and the difference is dramatic: 8 oz of flour by weight is roughly 1.9 cups, not one. If a recipe lists chocolate, cheese, or butter in ounces, it almost always means weight — use a scale, not a measuring cup.
How it’s calculated
Cups = fluid ounces ÷ 8 and fluid ounces = cups × 8, the exact US customary definitions (NIST Handbook 44): 1 US cup = 8 US fl oz = 236.588 mL and 1 US fl oz = 29.5735 mL, which the milliliter row uses. Weight ounces are a separate unit (1 oz = 28.3495 g) and depend on the ingredient’s density; the flour and sugar figures in the text use King Arthur reference weights (120 g and 200 g per cup).
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Common mistakes
- Reading recipe ounces as fluid ounces when weight was meant — cream cheese, chocolate, and pasta are sold and measured by weight.
- Mixing systems: the imperial fluid ounce is 28.41 mL vs the US 29.57 mL, and a metric cup is 250 mL, about 6% larger than a US cup.
- Assuming 8 oz of any dry ingredient equals 1 cup — that only holds for water-like liquids.
Frequently asked questions
How many ounces are in a cup?
Exactly 8 US fluid ounces of volume. On a scale it depends on the ingredient: a cup of water weighs about 8.3 oz, a cup of flour only about 4.2 oz.
How many cups is 8 oz?
8 fluid ounces is exactly 1 cup. 8 weight ounces is 1 cup only for water-like liquids — 8 oz of flour on a scale is about 1.9 cups.
How do I convert cups to oz?
Multiply cups by 8 to get fluid ounces: 2 cups = 16 fl oz, ¾ cup = 6 fl oz, ⅓ cup ≈ 2.67 fl oz.
Are dry and liquid measuring cups different sizes?
No — both hold 8 fl oz (236.588 mL) per cup. Dry cups are shaped so you can level the top; liquid cups have a spout and headroom for pouring.
Is a US cup the same as a metric cup?
No. A US cup is 236.588 mL, the metric cup used in Australia and NZ is 250 mL, and the US “legal” cup on nutrition labels is 240 mL.