Convert fluid ounce (us) to cups
1 fl oz = 0.125 cup · Formula and table below. Converting the other way? Cups to Oz →
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Other units
- Liter (l) 0.02957353
- Milliliter (ml) 29.57353
- Deciliter (dl) 0.295735296
- Kiloliter (kl) 0.000029574
- Cubic meter (m³) 0.000029574
- Cubic centimeter (cm³) 29.57353
- Gallon (US) (gal) 0.0078125
- Gallon (UK) (gal) 0.006505267
- Quart (US) (qt) 0.03125
- Pint (US) (pt) 0.0625
- Fluid ounce (US) (fl oz) 1
- Cup (US) (cup) 0.125
- Tablespoon (US) (tbsp) 2
- Teaspoon (US) (tsp) 6
- Cup (metric) (cup) 0.118294118
Reviewed on by the Skala Convert team
Divide fluid ounces by 8. Sixteen fluid ounces is 2 cups.
How many cups is an ounce?
cups = fl oz ÷ 8
One US cup is exactly 8 US fluid ounces, so one fluid ounce is ⅛ cup. Everything else in the US kitchen system doubles from there: 2 cups make a pint, 2 pints a quart, 4 quarts a gallon.
- 2 fl oz = ¼ cup
- 4 fl oz = ½ cup
- 6 fl oz = ¾ cup
- 8 fl oz = 1 cup
- 12 fl oz = 1½ cups
- 16 fl oz = 2 cups (1 pint)
- 32 fl oz = 4 cups (1 quart)
- 64 fl oz = 8 cups (½ gallon)
Is 8 oz of flour one cup?
No — and this is the mistake behind most "oz to cups" searches. A recipe that says 8 oz of flour means weight, not volume. Eight ounces of flour by weight is about 1¾ to 2 cups, because a cup of all-purpose flour weighs roughly 120–125 g (4.25–4.5 oz). The "8 oz = 1 cup" rule only works for water and liquids of similar density.
If the recipe writes fl oz, it is volume and divides by 8. If it writes plain oz next to a dry ingredient, weigh it — see ounces to grams.
Why does a measuring cup show 8 oz and 240 mL?
The exact US cup is 236.6 mL, but American nutrition labels are allowed to round it to 240 mL, and many measuring cups print that rounded figure. The 1.4% difference never matters in a soup; it can matter in a large batch of bread.
Who defines the cup as 8 fluid ounces?
US customary law. NIST Special Publication 811, the US guide to the SI lists the cup as 2.365882 × 10−4 m³ — half a US pint, exactly 8 fluid ounces of 1/128 gallon each. For nutrition labels the FDA rounds both: under 21 CFR 101.9, 1 cup means 240 mL and 1 fl oz means 30 mL, which keeps the 8-to-1 ratio.
Formula
Cups = Fluid ounce (US) × 0.125
10 fl oz = 1.25 cup
Conversion table
| fl oz | cup |
|---|---|
| 1 | 0.125 |
| 2 | 0.25 |
| 5 | 0.625 |
| 10 | 1.25 |
| 20 | 2.5 |
| 25 | 3.125 |
| 50 | 6.25 |
| 100 | 12.5 |
Charts for this conversion
Frequently asked questions
How many cups is 16 oz?
Two cups, if the ounces are fluid ounces.
Is 8 oz always 1 cup?
Only for liquids measured in fluid ounces. Eight ounces of flour by weight is about 1¾ to 2 cups.
How many oz in a quart?
32 US fluid ounces, or 4 cups.