Cups to Ounces Converter: Fluid Ounces and Ounces by Weight
Cups to Ounces Converter
Convert cups to fluid ounces and back, for US, metric, imperial and other cups, with fractions like 1/3 and 1 1/2 understood. A US cup is exactly 8 US fluid ounces, but a cup of flour weighs about 4.2 ounces and a cup of honey about 12, so pick an ingredient and the page also gives the ounces by weight, which is what a scale reads.
Fractions work: type 1/2, 3/4 or 1 1/2.
What this volume weighs
Where it sits among everyday containers
Every factor here is exact by definition. The US gallon is 231 cubic inches and the inch is exactly 2.54 centimetres, which makes the US fluid ounce exactly 29.5735295625 millilitres, since there are 128 of them in a gallon. The imperial gallon is defined as exactly 4.54609 litres and holds 160 imperial fluid ounces, which puts the imperial fluid ounce at exactly 28.4130625 millilitres. The ounce of weight, the avoirdupois ounce, is exactly 28.349523125 grams under the international yard and pound agreement of 1959, and it measures mass rather than volume: what a fluid ounce of something weighs depends entirely on what it is. Weights shown here use typical densities and are close enough for cooking, not for laboratory work. The CSV, image and printed report contain the values you entered, nothing preloaded.
How to use this tool
Type the number of cups, as a decimal or a fraction such as 3/4 or 1 1/2, and the answer in US fluid ounces appears at once, with imperial fluid ounces, millilitres and a measuring spoon breakdown alongside. The Swap button turns it round to go from ounces to cups. Both unit lists include every common cup, so a metric cup from an Australian recipe or the 240 ml cup on a US nutrition label converts just as easily.
The ingredient box answers the other question people mean when they ask for cups in ounces: what does it weigh? Pick flour, sugar, butter or any of 57 ingredients and the orange card and the chart show the weight in ounces and grams. The fluid ounce figure does not change, because it is a volume; the weight does, because it depends on what is in the cup.
What the calculation is doing
A US cup is defined as half a US pint, which is 8 US fluid ounces. Since the US gallon is exactly 231 cubic inches and holds 128 fluid ounces, a cup is exactly 236.5882365 millilitres and a fluid ounce exactly 29.5735295625. Converting cups to fluid ounces is multiplication by 8 and nothing else.
Other cups are different sizes, so their answer is not a round 8. A metric cup is 250 ml, 8.45 US fluid ounces. An imperial cup is half an imperial pint, 10 imperial fluid ounces, which is 9.61 US ones. Weight is a separate calculation again: volume times the density of the ingredient, which the page takes from measured grams per level cup.
Cups to ounces chart
| US cups | US fl oz | Imperial fl oz | Millilitres | Tablespoons |
|---|---|---|---|---|
| 1/8 | 1 | 1.04 | 29.6 | 2 |
| 1/4 | 2 | 2.08 | 59.1 | 4 |
| 1/3 | 2.67 | 2.78 | 78.9 | 5.33 |
| 1/2 | 4 | 4.16 | 118.3 | 8 |
| 2/3 | 5.33 | 5.55 | 157.7 | 10.67 |
| 3/4 | 6 | 6.25 | 177.4 | 12 |
| 1 | 8 | 8.33 | 236.6 | 16 |
| 1 1/2 | 12 | 12.49 | 354.9 | 24 |
| 2 | 16 | 16.65 | 473.2 | 32 |
| 3 | 24 | 24.98 | 709.8 | 48 |
| 4 | 32 | 33.31 | 946.4 | 64 |
| 8 | 64 | 66.61 | 1,892.7 | 128 |
| 16 | 128 | 133.23 | 3,785.4 | 256 |
Every row opens the converter on that amount. Exact by definition: 8 US fluid ounces to the US cup.
Every cup, in ounces
The word cup covers at least seven different volumes. For most recipes the difference between a US cup and a metric cup, about 6 percent, is harmless. For baking and for anything scaled up, pick the right one.
| Cup | Millilitres | US fl oz | Imperial fl oz | Where you meet it |
|---|---|---|---|---|
| US cups | 236.59 | 8 | 8.33 | American recipes and measuring cups |
| US legal cups | 240 | 8.12 | 8.45 | US nutrition labels |
| Metric cups | 250 | 8.45 | 8.8 | Australia, New Zealand, Canada, South Africa |
| Imperial cups | 284.13 | 9.61 | 10 | older British recipes |
| Canadian cups, traditional | 227.3 | 7.69 | 8 | older Canadian recipes |
| Japanese cups | 200 | 6.76 | 7.04 | Japanese recipes |
| Rice cooker cups | 180.39 | 6.1 | 6.35 | rice cookers |
A cup of common ingredients, in ounces by weight
This is where cups and ounces part company. The table gives what one level US cup weighs, which is the number to use when a recipe lists an ingredient in ounces and you only have a measuring cup, or the other way round.
| Ingredient, 1 level US cup | Ounces by weight | Grams | Fluid ounces |
|---|---|---|---|
| All purpose flour | 4.23 | 120 | 8 |
| Bread flour | 4.23 | 120 | 8 |
| Whole wheat flour | 4.23 | 120 | 8 |
| Almond flour | 3.39 | 96 | 8 |
| Granulated sugar | 6.98 | 198 | 8 |
| Brown sugar, packed | 7.51 | 213 | 8 |
| Confectioners sugar | 3.99 | 113 | 8 |
| Butter | 8.01 | 227 | 8 |
| Honey | 11.85 | 336 | 8 |
| Maple syrup | 11.01 | 312 | 8 |
| Milk | 8.01 | 227 | 8 |
| Heavy cream | 8.01 | 227 | 8 |
| Vegetable oil | 6.98 | 198 | 8 |
| Peanut butter | 9.52 | 270 | 8 |
| Rolled oats | 3.99 | 113 | 8 |
| Cocoa powder | 2.96 | 84 | 8 |
| Chocolate chips | 6 | 170 | 8 |
| Grated cheese | 3.99 | 113 | 8 |
| Chopped walnuts | 3.99 | 113 | 8 |
| Raisins | 5.26 | 149 | 8 |
| Sour cream | 8.01 | 227 | 8 |
| Cornstarch | 3.95 | 112 | 8 |
Weights per level US cup from the King Arthur Baking ingredient chart. Flours and powders are spooned into the cup and levelled, not scooped.
A worked check you can repeat on paper
Take 1 1/2 US cups. At 8 fluid ounces a cup that is 12 US fluid ounces, the size of a US can of soda. In millilitres it is 1.5 times 236.588, which is 354.9 ml, and dividing by 28.413 ml gives 12.49 imperial fluid ounces.
Now make it flour. One level US cup of all purpose flour is 120 grams, and an ounce of weight is 28.3495 grams, so a cup weighs 4.233 ounces and a cup and a half 6.35. The same cup and a half of honey, at 336 grams a cup, weighs 17.78 ounces. Twelve fluid ounces either way.
Mistakes that catch people out
Measuring a solid in fluid ounces. Eight ounces of chocolate is a weight. Filling a cup to the 8 oz line with chips gives about 6 ounces of chocolate, a quarter short.
Scooping flour. Pushing the cup into the bag packs it down and can add a fifth more flour. Spoon it in and level it, or weigh it.
Using a US cup for an Australian recipe. The metric cup is 250 ml, 6 percent more. In a cake with three cups of flour that is close to an extra 3 tablespoons.
Treating UK and US ounces as the same. An imperial fluid ounce is 4 percent smaller, and a UK recipe that says ounces for a solid means weight in any case.
Reading a measuring jug from above. Put it on a flat surface and read at eye level, from the bottom of the curved surface.
Popular calculations
Each opens the converter on that amount with its own address, and every value can be changed once it is open.
Cups to ounces
Ounces to cups
Other cups and ounces
A cup of an ingredient, in ounces by weight
Other amounts of flour, sugar and butter
How this was checked
The conversion factors come from the definitions: the US gallon of 231 cubic inches, the inch of exactly 2.54 cm, and the imperial gallon of exactly 4.54609 litres. The engine is the same one behind the oz to ml and ml to cups converters on this site, tested in Node before it went near the page: 1 US cup gave exactly 8 US fluid ounces, 1 metric cup 8.4535, and 1 imperial cup exactly 10 imperial fluid ounces. Ingredient weights are the per cup figures from the King Arthur Baking chart, converted at 28.349523125 grams to the ounce.
Every address in the lists above was then opened and checked for a distinct title, the right answer, charts that render, and clean CSV, image and print output containing only that conversion, at desktop, tablet and phone widths.
Common questions
How many ounces are in a cup?
8 US fluid ounces in a US cup, by definition. A metric cup of 250 ml is 8.45 US fluid ounces, an imperial cup is 10 imperial fluid ounces, and the 240 ml cup on US nutrition labels is 8.12 US fluid ounces.
Is 8 ounces always a cup?
Only for liquids measured by volume. A cup of flour weighs about 4.2 ounces, a cup of sugar about 7 and a cup of honey almost 12. When a recipe gives a solid ingredient in ounces, it means weight, and it needs a scale rather than a cup.
How many ounces are in half a cup?
4 US fluid ounces, which is also 8 tablespoons or 118.3 ml. By weight, half a cup of butter is 4 ounces, one US stick, and half a cup of all purpose flour is about 2.1 ounces.
How many cups are 16 ounces?
2 US cups, if the ounces are fluid ounces. That is also one US pint. Sixteen ounces of flour by weight is closer to 3.8 cups.
How many ounces are in a cup of flour?
About 4.23 ounces, or 120 grams, for all purpose flour spooned into the cup and levelled. Scooped straight from the bag it can reach 5 ounces, which is the most common reason baking comes out dry.
Are US and UK fluid ounces the same?
No. A US fluid ounce is 29.57 ml and an imperial fluid ounce, used in the UK, is 28.41 ml, about 4 percent smaller. A US cup is 8.33 imperial fluid ounces.
Related Calculators and Reference
- Oz to ML Converter: fluid ounces to millilitres, with the ounce of weight kept apart.
- ML to Cups Converter: for recipes written in millilitres.
- Cups to Grams Converter: the ingredient weights in grams, for a kitchen scale.
- Grams to Cups Converter: the other way round, from a weighed recipe to cups.
- Tablespoons to Cups Converter: for the smaller measures.
- NIST Special Publication 811: the definitions of the US and imperial units used here.