Cups to Ounces Converter
Choose an ingredient, enter a number of cups and read the answer in weight ounces, US fluid ounces or imperial fluid ounces.
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Created by the Reeliy Editorial Team. Last updated: Oct 19, 2026
Two different ounces
The word ounce covers two units that are easy to confuse. The ounce (oz) measures weight and equals 28.35 g; it is what a kitchen scale shows. The fluid ounce (fl oz) measures volume: a US fluid ounce is 29.57 ml and an imperial fluid ounce is 28.41 ml.
Only the weight ounce depends on the ingredient, because a cup of honey weighs more than a cup of flour while both fill the same space. The fluid ounce answers ignore the ingredient menu.
The familiar rule that a cup is 8 ounces holds for the US customary cup measured in fluid ounces. Our 240 ml legal cup is 8.115 US fluid ounces, and an imperial cup is exactly 10 imperial fluid ounces.
How to convert cups to ounces
- Select the ingredient. It matters only for the weight option.
- Enter the number of cups and pick US Legal Cups or Imperial Cups.
- In the To menu choose Ounces (weight), US Fluid Ounces or Imp. Fluid Ounces.
ounces (weight) = cups × cup volume (ml) × density (g/ml) ÷ 28.3495
fluid ounces = cups × cup volume (ml) ÷ 29.5735 (US) or ÷ 28.4131 (imperial)Answers are rounded to three decimals.
Worked examples
- 1 cup of water in ounces: 240 g ÷ 28.3495 = 8.466 oz, which is also 8.115 US fluid ounces.
- 2 cups of flour: 2 × 240 × 0.52 = 249.6 g, or 8.804 oz.
- 1.5 cups of honey: 1.5 × 240 × 1.4 = 504 g, or 17.778 oz.
- 1 imperial cup of butter: 284.13 × 0.959 = 272.5 g, or 9.612 oz.
Cups to ounces charts
| Ingredient | US legal cup (oz) | Imperial cup (oz) |
|---|---|---|
| Water | 8.466 | 10.022 |
| Flour | 4.402 | 5.212 |
| Granulated Sugar | 7.577 | 8.97 |
| Brown Sugar | 7.154 | 8.469 |
| Salt | 10.159 | 12.027 |
| Butter | 8.119 | 9.612 |
| Vegetable Oil | 7.772 | 9.201 |
| Milk | 8.779 | 10.393 |
| Runny Honey | 11.852 | 14.031 |
| Rice | 6.773 | 8.018 |
| US legal cups | US fluid ounces | Imperial fluid ounces |
|---|---|---|
| 1/4 | 2.029 | 2.112 |
| 1/3 | 2.705 | 2.816 |
| 1/2 | 4.058 | 4.223 |
| 2/3 | 5.41 | 5.631 |
| 3/4 | 6.087 | 6.335 |
| 1 | 8.115 | 8.447 |
| 2 | 16.231 | 16.894 |
| 4 | 32.461 | 33.787 |
Common mix-ups
- A scale reads weight ounces and a measuring jug reads fluid ounces. A cup of flour is about 4.4 oz on a scale yet it fills 8.1 US fluid ounces of jug.
- Only water-like liquids come close to "8 ounces per cup" in weight. Honey is nearly 12 oz per cup and ground almonds about 4.
- Check which cup and which fluid ounce your recipe uses. US and imperial fluid ounces differ by about 4%.
For metric weights see cups to grams, and for the reverse direction use ounces to cups.
Frequently asked questions
How many ounces are in a cup?
By volume, a US legal cup is 8.115 US fluid ounces and an imperial cup is 10 imperial fluid ounces. By weight it depends on the ingredient: 8.466 oz for water, 4.402 oz for flour and 11.852 oz for honey.
Are fluid ounces and ounces the same?
No. A fluid ounce is a unit of volume and an ounce is a unit of weight. They are only close to equal for water, where one US fluid ounce weighs about 1.04 oz.
How many ounces of flour are in a cup?
A US legal cup of flour weighs about 4.402 oz (124.8 g). An imperial cup weighs about 5.212 oz.
Why does the ingredient not change the fluid ounce answer?
Fluid ounces measure volume, and a cup is also a volume, so the two convert directly with no density involved.
References
- NIST Special Publication 811, Guide for the Use of the International System of Units (SI)
- U.S. Code of Federal Regulations, 21 CFR 101.9, Nutrition labeling of food (household measures)
- USDA FoodData Central, household measure weights for foods
Cite this converter and page
If you use this page in your work, you can cite it as:
Reeliy Editorial Team. (2026). Cups to Ounces Converter. Reeliy. https://reeliy.com/converters/convert-cups-to-oz“Cups to Ounces Converter.” Reeliy, 2026, https://reeliy.com/converters/convert-cups-to-oz.