Cups to Ounces Converter
How many ounces are in a cup — and why the answer has two versions
One US cup holds 8 fluid ounces. That is a volume measurement and it is true for any liquid — water, milk, oil or stock.
Ask how many ounces are in a cup and you will get two different right answers, which is exactly why recipes go wrong. A US cup always holds 8 fluid ounces of volume. But a cup of an ingredient almost never weighs 8 ounces, because weight depends on what you put in the cup.
This page converts cups to fluid ounces — the volume answer. If you need the weight of a cup of flour or sugar, use the grams and ounces converters linked below, which take the ingredient's density into account.
Reference table
| cups | fluid ounces | tablespoons | millilitres |
|---|---|---|---|
| ⅛ cup | 1 fl oz | 2 tbsp | 29.57 ml |
| ¼ cup | 2 fl oz | 4 tbsp | 59.15 ml |
| ⅓ cup | 2.66 fl oz | 5.33 tbsp | 78.78 ml |
| ½ cup | 4 fl oz | 8 tbsp | 118.3 ml |
| ⅔ cup | 5.34 fl oz | 10.67 tbsp | 157.8 ml |
| ¾ cup | 6 fl oz | 12 tbsp | 177.4 ml |
| 1 cup | 8 fl oz | 16 tbsp | 236.6 ml |
| 1½ cup | 12 fl oz | 24 tbsp | 354.9 ml |
| 2 cup | 16 fl oz | 32 tbsp | 473.2 ml |
| 3 cup | 24 fl oz | 48 tbsp | 709.8 ml |
| 4 cup | 32 fl oz | 64 tbsp | 946.4 ml |
| 6 cup | 48 fl oz | 96 tbsp | 1420 ml |
| 8 cup | 64 fl oz | 128 tbsp | 1893 ml |
Fluid ounces vs weight ounces: the difference that ruins recipes
A fluid ounce measures how much space something takes up. A weight ounce measures how heavy it is. They share a name for a historical reason — one fluid ounce of water happens to weigh almost exactly one ounce — and that coincidence is the entire source of the confusion.
The coincidence only holds for water. A cup of water weighs about 8.3 ounces, which is close enough to 8 that nobody notices. A cup of all-purpose flour weighs about 4.4 ounces — barely half of what the fluid-ounce number suggests. A cup of honey weighs about 12 ounces.
The practical rule: if the recipe lists a liquid in ounces, it almost certainly means fluid ounces. If it lists flour, sugar, butter, chocolate or nuts in ounces, it means weight, and you need a scale or a density-aware converter.
| Ingredient | 1 cup by volume | 1 cup by weight |
|---|---|---|
| Water | 8 fl oz | 8.3 oz |
| Whole milk | 8 fl oz | 8.6 oz |
| All-purpose flour | 8 fl oz | 4.4 oz |
| Granulated sugar | 8 fl oz | 7.1 oz |
| Brown sugar (packed) | 8 fl oz | 7.8 oz |
| Butter | 8 fl oz | 8.0 oz |
| Honey | 8 fl oz | 12.0 oz |
| Rolled oats | 8 fl oz | 3.2 oz |
The cup measurements worth memorising
The awkward ones are the thirds. A third of a cup is not a whole number of tablespoons, which is why ⅓ and ⅔ cup measures exist as their own scoops. If you only have tablespoons, 5 tablespoons plus 1 teaspoon is the accurate substitute for ⅓ cup.
- 1 cup = 8 fl oz = 16 tablespoons = 48 teaspoons
- ¾ cup = 6 fl oz = 12 tablespoons
- ⅔ cup = 5⅓ fl oz = 10 tablespoons + 2 teaspoons
- ½ cup = 4 fl oz = 8 tablespoons
- ⅓ cup = 2⅔ fl oz = 5 tablespoons + 1 teaspoon
- ¼ cup = 2 fl oz = 4 tablespoons
- ⅛ cup = 1 fl oz = 2 tablespoons
Cups outside the United States
A recipe that says 'cup' does not mean the same thing everywhere, and the gap is big enough to matter in baking.
The US customary cup is 236.6 ml. Australia and New Zealand use a 250 ml metric cup — about 6% larger. Older British recipes may use a 284 ml imperial cup, which is 20% larger than a US cup. US nutrition labels use a rounded 240 ml 'legal cup'.
Six percent sounds harmless until you scale it. A cake recipe using three cups of flour written in Australia and measured with US cups is short by roughly a fifth of a cup — enough to change the crumb.
| Cup type | Millilitres | US fluid ounces | Where it is used |
|---|---|---|---|
| US customary cup | 236.6 ml | 8.0 fl oz | United States recipes |
| US legal cup | 240 ml | 8.1 fl oz | US nutrition labels |
| Metric cup | 250 ml | 8.5 fl oz | Australia, New Zealand, Canada |
| Imperial cup | 284.1 ml | 9.6 fl oz | Older British recipes |
| Japanese cup | 200 ml | 6.8 fl oz | Japanese recipes |
How to measure fluid ounces accurately
- Use a clear liquid measuring jug, not a dry cup — you cannot fill a dry cup to the brim without spilling, so people under-fill them.
- Put the jug on a flat surface and read it at eye level. Reading from above routinely over-pours by 5–10%.
- For anything under 2 fluid ounces, use tablespoons instead. Jug markings that low are guesswork.
- Sticky liquids like honey and syrup leave a lot behind. Oil the cup first, or weigh them instead.
Frequently asked questions
How many ounces are in a cup?
A US cup holds 8 fluid ounces. If you mean weight ounces, the answer depends entirely on the ingredient — a cup of flour weighs about 4.4 oz while a cup of honey weighs about 12 oz.
How many ounces are in a half cup?
Half a US cup is 4 fluid ounces, which is also 8 tablespoons or about 118 ml.
Is 8 oz the same as 1 cup?
For liquids measured by volume, yes — 8 fluid ounces is 1 cup. For dry ingredients weighed on a scale, no. 8 ounces of flour by weight is closer to 1¾ cups.
How many ounces in 2 cups?
2 US cups is 16 fluid ounces, which is one US pint or about 473 ml.
Why does my measuring jug show a different number of ounces?
Check whether it is marked in US or imperial fluid ounces. An imperial fluid ounce is about 4% smaller than a US one, and imperial jugs put 10 fluid ounces in a half-pint instead of 8.