Convert cups to fluid ounces

1 cup=8.11537fl oz

Use the converter below to change any cups value into fluid ounces instantly — with formula, conversion table, and real-world examples.

You have

Equals

8.115365

Conversion formula

Forward

fluid ounces = cups × 8.11537

Reverse

cups = fluid ounces × 0.1232

Example: 10 cup × 8.11537 = 81.1537 fl oz.

About both units

From

Cup

cup

The US cup equals 240 millilitres in common usage (legally defined as 236.588 ml). The metric cup (Australia, NZ) is 250 ml; the UK "cup" is 284 ml but rarely used in recipes. Cooking recipes from the US dominate online, so 240 ml is the safe default for "cup".

Real-world: 1 cup of water = 240 g = 240 ml. 1 cup of all-purpose flour weighs about 125 g. A Starbucks Tall is 12 fl oz = 1.5 cups.

Read full cup reference →

Fluid Ounce

fl oz

The US fluid ounce equals 29.5735 millilitres — 1/128 of a US gallon. The UK fluid ounce (28.41 ml) is slightly smaller. Used for beverage can sizes in the US, cosmetic product sizes and many US cooking recipes. Do not confuse with the ounce of mass (28.35 g).

Real-world: A US soda can is 12 fl oz (355 ml). A Starbucks Tall is 12 fl oz; Grande is 16; Venti is 20.

Read full fluid ounce reference →

Cup to Fluid Ounce conversion table

Common cups to fluid ounces values for quick reference.

Cup (cup)	Fluid Ounce (fl oz)
1 cup	8.11537 fl oz
2 cup	16.2307 fl oz
5 cup	40.5768 fl oz
10 cup	81.1537 fl oz
20 cup	162.307 fl oz
50 cup	405.768 fl oz
100 cup	811.537 fl oz
200 cup	1,623.07 fl oz
500 cup	4,057.68 fl oz
1,000 cup	8,115.37 fl oz

Tips & common mistakes

Quick tips

US cup = 240 ml common; 236.6 ml legal; UK cup = 284 ml; metric cup (AU/NZ) = 250 ml.
Weights (grams) are more reliable than cups — a cup of flour can vary 30% depending on how packed.
For baking, always use the recipe author's country convention.

Avoid these

Using a UK 284 ml cup for a US recipe calling for 240 ml — 18% overshoot.
Treating all dry ingredients as 1 cup = 240 g — only true for water.
Using a coffee mug as a "cup" — mugs vary 200–400 ml.

Frequently asked questions

How many fluid ounces in a cup?

One cup equals 8.11537 fluid ounces.

How do I convert cups to fluid ounces?

Multiply the cup value by 8.11537 to get the equivalent in fluid ounces.

What is 100 cups in fluid ounces?

100 cups equals 811.537 fluid ounces.

Is a cup bigger than a fluid ounce?

Yes. 1 cup equals 8.11537 fluid ounces, so one cup is larger.

How to convert cups to fluid ounces without a calculator?

Multiply by 8.12 for a quick estimate; use a calculator for precise results.

Related volume conversions

📊 See full comparison matrix →

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Convert cups to fluid ounces

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