Convert Fluid Ounce to Cup (fl ozcup)

The US fluid ounce is the standard unit for beverage portions, cocktail recipes, and personal-care product sizes.

0.123223
1 fl oz0.123223 cupNIST · BIPM accuracy

Fluid Ounce to Cup Conversion Table

10 common values
Fluid OunceCup
1 fl oz0.123223 cup
2 fl oz0.246446 cup
5 fl oz0.616115 cup
10 fl oz1.23223 cup
20 fl oz2.464461 cup
50 fl oz6.161152 cup
100 fl oz12.322304 cup
200 fl oz24.644608 cup
500 fl oz61.61152 cup
1,000 fl oz123.22304 cup

How to Convert Fluid Ounce to Cup Manually

Step by Step

Converting fluid ounces to cups is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

  1. 1
    Take your value in fluid ounces
    Start with the number of fluid ounces (fl oz) you want to convert.
  2. 2
    Multiply by 0.123223
    The conversion factor from fl oz to cup is 0.123223. Multiply your value by this number.
  3. 3
    Read the result in cups
    The result is your value in cups (cup).
Practical Examples
1 fl oz
equals
0.123223 cup
5 fl oz
equals
0.616115 cup
10 fl oz
equals
1.23223 cup
25 fl oz
equals
3.080576 cup
100 fl oz
equals
12.322304 cup

Formula

Multiply the value in fluid ounces by 0.123223. For the reverse direction, multiply by 8.115365.

Forwardcup = fl oz × 0.123223
Reversefl oz = cup × 8.115365
Example: 10 fl oz × 0.123223 = 1.23223 cup

Tips

Use these in everyday conversions
  • 1 US fl oz ≈ 29.6 ml; 1 UK fl oz ≈ 28.4 ml.
  • 8 US fl oz ≈ 1 US cup ≈ 237 ml.
  • Use ml to avoid ambiguity between US and UK fluid ounces.

Common Mistakes

Avoid these
  • Mixing US and UK fluid ounces — 16 fl oz (US) = 473 ml vs. 16 fl oz (UK) = 455 ml.
  • Confusing fluid ounce (volume) with avoirdupois ounce (mass).
  • Assuming 1 fl oz = 1 oz by weight — only true for pure water and approximately.

About Fluid Ounce and Cup

What is the Fluid Ounce?

The US fluid ounce equals exactly 29.5735295625 milliliters and is the standard small-volume unit for beverages, cocktails, personal-care products, and cooking in the United States. It is distinct from the (weight) ounce: 1 fluid ounce of water weighs about 1 ounce by weight at room temperature, but other liquids may weigh more or less. Soft-drink cans (12 fl oz), beer bottles (12 fl oz), shampoo bottles, and skin-cream tubs all label volume in fluid ounces. The US fluid ounce is slightly different from the UK imperial fluid ounce (28.4131 mL — about 4% smaller), reflecting the different gallon definitions. The US fl oz relates to the gallon (128 fl oz = 1 gal), the cup (8 fl oz = 1 cup), the tablespoon (2 tbsp = 1 fl oz), and the milliliter (1 fl oz ≈ 29.57 mL). Cocktail recipes universally use fluid ounces.

  • US beverage and soda can sizes (12 fl oz)
  • Cosmetic and personal-care product volumes
  • US fluid recipes and cocktail measures
Real-world examples

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

What is the Cup?

The US cup equals exactly 240 milliliters (a definition standardized for nutrition labeling; the legal volume for cooking is 236.588 mL, derived from 8 US fluid ounces). The cup is the cornerstone of American baking and home cooking, with virtually every US recipe using volume measurements rather than the weight measurements common in European cooking. Standard measuring-cup sets include 1, ½, ⅓, and ¼ cup sizes. The metric cup (used in Australia, New Zealand, and increasingly in international recipes) is exactly 250 mL — slightly larger than the US cup. The cup relates to the gallon (16 cups = 1 gal), the pint (2 cups = 1 pt), the fluid ounce (8 fl oz = 1 cup), the tablespoon (16 tbsp = 1 cup), and the milliliter (1 cup ≈ 237–240 mL). American baking-by-volume is sometimes criticized internationally for its variability compared to gram-based measurements.

  • US cooking and baking recipes
  • Cereal and beverage serving sizes in US nutrition labels
  • Volume estimation when no scale is available
Real-world examples

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.

Learn About Both Units

🧪 Reference

What is the Fluid Ounce?

Read the unit page →
🧪 Reference

What is the Cup?

Read the unit page →

Fluid Ounce to Cup FAQ

5 questions
How many cups in a fluid ounce?
One fluid ounce equals 0.123223 cups.
How do I convert fluid ounces to cups?
Multiply the fluid ounce value by 0.123223 to get the equivalent in cups.
What is 100 fluid ounces in cups?
100 fluid ounces equals 12.322304 cups.
Is a fluid ounce bigger than a cup?
No. 1 fluid ounce equals 0.123223 cups, so one fluid ounce is smaller.
How to convert fluid ounces to cups without a calculator?
Multiply by 0.12 for a quick estimate; use a calculator for precise results.

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