How many ounces in a cup, liquid and dry
There are 8 fluid ounces in a US cup. A cup of flour weighs 4.41 oz on a scale.
Fluid ounces in 1 cup
1 cup x 8 fl oz per cup = 8 fl oz
1 cup = 8 fl oz, NIST SP 811. How we calculate this
From: Cups. Amount: 1 cup. Ingredient: Water or any liquid (fluid ounces). Cup: US customary, 236.6 mL.
One US cup is 8 US fluid ounces, 236.588 mL under NIST SP 811. Ounces on a kitchen scale are weight, and a cup of all-purpose flour weighs 125 g, or 4.41 oz, per USDA FoodData Central. A cup of water weighs 237 g, or 8.36 oz. So "8 ounces in a cup" holds for fluid ounces and fails for flour.
Enter cups or ounces and the converter fills in the other. Pick the cup your recipe uses; US customary is the default. For weight, choose an ingredient and the result switches from fluid ounces to ounces on a scale, using the USDA cup weight for that food.
Quick answer: how many ounces are in a cup?
A US cup holds 8 US fluid ounces, which is 236.588 mL. That answer covers liquids measured by volume. On a kitchen scale the ounces depend on the food. USDA FoodData Central cup weights put a cup of all-purpose flour at 4.41 oz, water at 8.36 oz and butter at 8.01 oz.
Key takeaways
- Fluid ounces (fl oz) measure volume; ounces on a scale measure weight.
- By volume a US cup is always 8 US fl oz. A metric cup is 8.45 and an Imperial cup 9.61 US fl oz.
- Half a cup is 4 fl oz, and 1 1/2 cups is 12 fl oz.
- 1 US fl oz is 29.5735 mL; food labels round it to 30 mL.
Worked example: how many ounces in a cup, by volume and by weight
By volume, one US cup is 8 fl oz, so 2 fl oz is 1/4 cup, which is 59.147 mL. Going up, 3 cups is 24 fl oz and 32 fl oz is 4 cups. For odd amounts divide by 8: 62 fl oz is 62 / 8 = 7.75 cups, or 7 3/4 cups, and 12 fl oz is 1 1/2 cups.
The same cup on a scale gives a different number. One cup of all-purpose flour is 125 g. Divide by 28.3495 g per ounce and you get 4.41 oz. So 1.5 cups of flour is 187.5 g, or 6.61 oz, and 2 1/8 cups is 2.125 x 125 = 265.6 g, or 9.37 oz.
The chain for one ingredient shows why the two answers split. One cup of olive oil is 8 fl oz of volume, 236.588 mL. USDA lists that cup at 216 g, so it weighs 7.62 oz. Honey fills the same 8 fl oz and weighs 339 g, or 11.96 oz. Water sits between them at 237 g, or 8.36 oz, which is why water comes close to "8 ounces" both ways.
| Cups | US fl oz | mL | Tablespoons |
|---|---|---|---|
| 1/8 | 1 | 29.57 | 2 |
| 1/4 | 2 | 59.15 | 4 |
| 1/3 | 2.67 | 78.86 | 5 tbsp + 1 tsp |
| 1/2 | 4 | 118.29 | 8 |
| 2/3 | 5.33 | 157.73 | 10 tbsp + 2 tsp |
| 3/4 | 6 | 177.44 | 12 |
| 1 | 8 | 236.59 | 16 |
| 1 1/2 | 12 | 354.88 | 24 |
| 2 | 16 | 473.18 | 32 |
| 3 | 24 | 709.76 | 48 |
| 4 | 32 | 946.35 | 64 |
| Cup | mL | US fl oz | Imperial fl oz | Source |
|---|---|---|---|---|
| US customary cup | 236.588 | 8.00 | 8.33 | NIST SP 811, Appendix B.8 |
| US labeling cup | 240 | 8.12 | 8.45 | 21 CFR 101.9(b)(5)(viii) |
| Metric cup | 250 | 8.45 | 8.80 | Defined as 250 mL |
| Imperial cup | 284.131 | 9.61 | 10.00 | 2 Imperial gills, NIST SP 811 |
| Ingredient (USDA record) | Grams per cup | Ounces by weight |
|---|---|---|
| Water, tap (173647, 8 fl oz serving) | 237 | 8.36 |
| Milk, whole (171265) | 244 | 8.61 |
| Olive oil (171413) | 216 | 7.62 |
| Honey (169640) | 339 | 11.96 |
| Peanut butter, smooth (172470) | 258 | 9.10 |
| Butter, salted (173410) | 227 | 8.01 |
| All-purpose flour (168894) | 125 | 4.41 |
| Bread flour (168896) | 137 | 4.83 |
| Whole wheat flour (168893) | 120 | 4.23 |
| Granulated sugar (169655) | 200 | 7.05 |
| Brown sugar, packed (168833) | 220 | 7.76 |
| Powdered sugar, unsifted (169656) | 120 | 4.23 |
| Cocoa powder, unsweetened (169593) | 86 | 3.03 |
| Semisweet chocolate chips (167976) | 168 | 5.93 |
| Cheddar, shredded (173414) | 113 | 3.99 |
| White rice, long grain, raw (169756) | 185 | 6.53 |
How we calculate this
Formula
Fluid ounces = cups x fluid ounces per cup.
1 cup x 8 fl oz per cup = 8 fl oz.
Your inputs
From: Cups. Amount: 1 cup. Ingredient: Water or any liquid (fluid ounces). Cup: US customary, 236.6 mL.
Sources
- NIST, Guide for the Use of the International System of Units (SI), Special Publication 811, Appendix B.8, 2008 edition (read 8 October 2026). It lists the US cup at 0.236 588 2 L, the US fluid ounce at 0.029 573 53 L and the Imperial gill at 0.142 065 3 L. A US cup holds 8 fl oz, and the Imperial cup is two gills, 284.131 mL, or 10 Imperial fluid ounces of 28.4131 mL. The pound is exactly 453.592 37 g, so the ounce, a sixteenth of it, is 28.349 523 125 g.
- FDA, 21 CFR 101.9(b)(5)(viii), the nutrition labeling rule, current text on the eCFR (read 8 October 2026). It sets the labeling cup at 240 mL, 1 fl oz at 30 mL and 1 oz of weight at 28 g for Nutrition Facts labels. The metric cup is 250 mL by definition.
- USDA Agricultural Research Service, FoodData Central, SR Legacy foods, published 2019 (read 8 October 2026). Each ingredient's grams per cup is its "1 cup" portion, and the record numbers are in the table above. For another cup size the weight scales with the volume: grams per cup x (cup mL / 236.588).
Limits
Each USDA cup weight assumes the usual fill for that food: spooned and leveled for flour, and packed for brown sugar, which USDA lists as its own entry. Baking soda, baking powder, yeast and cinnamon have only spoon portions in USDA, so their cup weight is the teaspoon or tablespoon weight times 48 or 16. The converter assumes a level measuring cup and cannot see how you filled it, and a drinking mug holds a different amount.
Video: How many fluid ounces in a cup, cups to fluid ounces and back
Is a cup 8 oz or 16 oz
A US cup is 8 fluid ounces. The 16 belongs to the pint: NIST lists the US liquid pint at 0.473 176 5 L, which is two cups, so 16 fl oz is 2 cups. The other 16 is weight, where 16 oz is 1 pound, 453.592 g. That has nothing to do with cups unless you know the ingredient. One pound of water is 1.91 cups, and one pound of flour is 453.592 / 125 = 3.63 cups. So 16 fl oz of milk is 2 cups, and 16 oz of flour on a scale is about 3 5/8 cups. A quart is 4 cups and a gallon is 16, on the cups in a gallon page. For spoons, 1 fl oz is 2 tablespoons, on the tablespoons in a cup page.
Fluid ounces vs ounces: what fl oz means
A fluid ounce is a volume, 29.5735 mL in the US. An ounce with no "fl" is a weight, 28.3495 g. They share a name because a fluid ounce of water weighs about one ounce: 29.5735 mL of water is 29.57 g, or 1.04 oz. For anything denser or lighter than water the two drift apart. A cup of honey is 8 fl oz and 11.96 oz by weight. A cup of cocoa powder is 8 fl oz and 3.03 oz by weight. Liquids in a US recipe mean fluid ounces. An "oz" with no "fl" on a package, and any number on a scale, means weight. When a recipe says "4 oz chocolate chips" it means weight, and that is about 2/3 cup, since a cup of chips is 5.93 oz.
How many ounces in a dry cup
A dry measuring cup holds the same 8 fl oz of volume as a liquid measuring cup; it is shaped so you can level it with a knife. There is no separate dry ounce unit in the kitchen. "Dry ounces" in practice means weight on a scale, and that number changes with the food. One cup of flour is 4.41 oz, sugar is 7.05 oz, packed brown sugar is 7.76 oz and shredded cheddar is 3.99 oz. "A dry cup is 8 dry ounces" is only true for an ingredient that weighs about the same as water. If a recipe gives dry ingredients in ounces, weigh them. If it gives cups, use the table above to see what that cup should weigh.
How many ounces in a cup of flour
USDA lists one cup of all-purpose flour at 125 g, which is 4.41 oz. The number depends on the flour and on the fill. USDA's bread flour cup is 137 g, or 4.83 oz, and its whole wheat cup is 120 g, or 4.23 oz. The all-purpose figure assumes a spooned and leveled cup, which is what the converter uses. Fill the cup another way and it holds a different weight, which is why flour charts disagree. A scale removes the question: set it to grams and use the table above to convert a cup recipe once. Weigh dry ingredients, where the fill changes the result, and measure water, milk and oil by volume. The grams to cups page has more flours and sugars.
Is a cup of flour the same weight as a cup of sugar
No. One cup of flour is 125 g and one cup of granulated sugar is 200 g, so the sugar weighs 60 percent more. The cups are the same size; the sugar packs more weight into the volume. Convert a recipe on the assumption that "1 cup = 8 oz" for both and you weigh out far too much flour. 8 oz of flour is 227 g, against the 125 g the recipe meant. If you convert a US recipe to weight, use each ingredient's own cup weight. Flour is 4.41 oz, sugar 7.05 oz, packed brown sugar 7.76 oz and butter 8.01 oz.
How many ounces in a cup of butter
USDA lists one cup of salted butter at 227 g, which is 8.01 oz, and one stick at 113 g, which is 3.99 oz. So one cup of butter is two sticks and 8 oz by weight, and it is also 8 fl oz by volume. Butter is the food in the table whose cup weighs closest to 8 oz. A cup of butter is half a pound: a pound is 453.592 g, or four sticks, or 2 cups. A tablespoon is 14.2 g, or half an ounce, so 4 tablespoons make a quarter cup. US recipes that say "8 oz butter" mean weight, which is still 2 sticks. Fluid ounces are a volume, so "8 fl oz of butter" describes the space it fills, and the scale happens to agree.
How many ounces in a cup of water or milk
One cup of water is 8 fl oz and weighs 237 g, or 8.36 oz, in USDA's 8 fl oz serving. Whole milk is 244 g per cup, 8.61 oz, so it weighs a little more than water. A mug is not a measuring cup. If a mug is your measure, pour it into a measuring cup once and see what it holds.
US, UK and metric cups
A US cup is 236.588 mL and 8 US fl oz. A metric cup, used in Australia and in Canadian and UK metric recipes, is 250 mL, which is 8.45 US fl oz. The old UK Imperial cup is 284.131 mL, which is 10 Imperial fl oz and 9.61 US fl oz. The Imperial fluid ounce is 28.4131 mL, smaller than the US fluid ounce at 29.5735 mL. So "a UK cup is 10 ounces" describes the Imperial cup and "a UK cup is 250 mL" describes the metric cup. The 240 mL cup is the FDA labeling cup on US Nutrition Facts panels, 8.12 US fl oz. The mL to cups page converts between all four.
How many ounces in a cup of rice, cheese or peanut butter
Raw long grain white rice is 185 g per cup in USDA, which is 6.53 oz. For the water to cook it, see the rice to water ratio page. Shredded cheddar is 113 g per cup, 3.99 oz, so an 8 oz block of cheddar (226.8 g) shreds to 2 cups. Smooth peanut butter is 258 g per cup, 9.10 oz. It is a paste, so pack it into a dry cup and level it, or weigh it. A cup of it is 8 fl oz of volume and 9.10 oz of weight.
Frequently asked questions
Is 4 oz the same as a cup? No. 4 fl oz is half a cup. On a scale, 4 oz is 113 g, which is one stick of butter or one cup of shredded cheddar.
How many cups is 12 oz? 12 fl oz is 1 1/2 cups. 12 oz by weight is 340 g, which is close to one cup of honey (339 g).
Is 1 cup always 8 ounces? By volume, a US cup is always 8 US fl oz. A metric cup is 8.45 and an Imperial cup is 9.61 US fl oz. By weight it depends on the food: butter is 8.01 oz, water 8.36 oz and flour 4.41 oz.
How many ounces is a cup of cocoa powder or chocolate chips? Cocoa is 86 g per cup, 3.03 oz. Semisweet chips are 168 g per cup, 5.93 oz, which is why a 12 oz bag holds about 2 cups.
What does a US fluid ounce measure in mL? 29.5735 mL. The FDA rounds it to 30 mL on food labels, and the Imperial fluid ounce is 28.4131 mL.
Conclusion
For liquids, count 8 fluid ounces to the US cup. For flour, sugar and other dry foods, weigh them or use the USDA cup weight in the converter, since a cup of flour weighs only 4.41 oz.
From our cookbooks: the cup weights above come up every time a pancake or muffin recipe lists flour and sugar by the cup. The breakfast recipes in Healthy Breakfast Cookbook give those amounts in cups, so this table turns them into weights for your scale.