Cups to Fluid Ounces Converter
Convert US cups to fluid ounces (cups to fl oz) for any recipe
1 US cup = 8 US fluid ounces. To convert cups to fluid ounces, multiply the cups by 8, so ½ cup = 4 fl oz and 2 cups = 16 fl oz.
Cups to Fluid ounces converter
Live1 US cup = 8 US fl oz = 236.59 mL.
- 2 stick
- 16 tbsp
- 48 tsp
- 236.58824 mL
How to convert cups to fluid ounces
The cup and the fluid ounce belong to the same US customary system, and they are tied together by definition. The US gallon is 231 cubic inches; it holds 128 fluid ounces and 16 cups. Divide one by the other and every cup holds exactly 8 fluid ounces, or about 236.59 mL. No rounding is involved, which is why the converter always gives clean numbers. Sticks of butter, teaspoons and milliliters are all on the cooking converter.
The catch is that “ounce” means two different things. A fluid ounce measures volume, the space a liquid takes up. An ordinary ounce measures weight. A cup of water holds 8 fl oz and happens to weigh a little over 8 oz, but a cup of flour also fills 8 fl oz while weighing only about 4.2 oz. When a recipe gives dry ingredients in ounces, it means weight, so use the cups to grams converter or the grams to ounces converter. For metric jugs, the mL to cups converter is the one you need.
Step by step
- Take the number of US cups (write fractions as decimals: ¾ = 0.75).
- Multiply by 8.
- The answer is in US fluid ounces; for UK recipes, see the imperial column in the chart below.
- For tablespoons, multiply the fluid ounces by 2.
See it on a scale
Worked examples
Three kitchen cases: ¾ cup of milk for pancakes, a 2-cup measuring jug, and 4½ cups of stock for soup.
0.75 cup × 8 = 6 fl oz
= 6 fl oz
2 cup × 8 = 16 fl oz
= 16 fl oz
4.5 cup × 8 = 36 fl oz
= 36 fl oz
Why does a US pint have 16 fl oz but a UK pint has 20?
A US pint is 16 US fluid ounces (473.18 mL) and a UK pint is 20 imperial fluid ounces (568.26 mL), because each system splits a different gallon into a different number of ounces.
The US gallon of 231 cubic inches is divided into 128 fluid ounces, while the imperial gallon of 4.54609 L is divided into 160. That makes the imperial fluid ounce slightly smaller (28.41 mL against 29.57 mL), even though the imperial pint is about 20.1% bigger.
Cups follow the pints. In the US a cup is half a pint, so it holds 8 fl oz; the traditional British cup is also half a pint, which makes it 10 imperial fl oz, or 284.13 mL. For a British recipe, set the Standard switch above to Imperial (UK). A pint of beer in a UK pub is the 568 mL imperial pint, so it holds about 19.2 US fl oz.
How many cups are in a quart, a pint and a gallon?
A US quart holds 4 cups (32 fl oz), a pint 2 cups (16 fl oz) and a gallon 16 cups (128 fl oz). Every step up the ladder doubles: cup, pint, quart, half gallon, gallon.
- 2 cups = 1 pint = 16 fl oz (473.18 mL)
- 2 pints = 1 quart = 32 fl oz (946.35 mL)
- 2 quarts = 1 half gallon = 64 fl oz (1,892.71 mL)
- 2 half gallons = 1 gallon = 128 fl oz (3,785.41 mL)
The old saying “a pint's a pound the world around” is only roughly true, and only for US pints of water: 16 fl oz of water weighs about 1.04 lb. An imperial pint of water weighs about 1.25 lb, so the rhyme fails in Britain.
A quart is close to a liter but not equal to one: it is 0.946 L. To express these amounts in liters, use the mL to liters converter.
Cups to fl oz conversion chart
US cups converted to US fluid ounces. Every result is exact because a cup is defined as 8 fluid ounces.
| Cups (cup) | Fluid ounces (fl oz) |
|---|---|
| 0.125 cup | 1 fl oz |
| 0.25 cup | 2 fl oz |
| 0.5 cup | 4 fl oz |
| 0.75 cup | 6 fl oz |
| 1 cup | 8 fl oz |
| 1.25 cup | 10 fl oz |
| 1.5 cup | 12 fl oz |
| 1.75 cup | 14 fl oz |
| 2 cup | 16 fl oz |
| 2.5 cup | 20 fl oz |
| 3 cup | 24 fl oz |
| 3.5 cup | 28 fl oz |
| 4 cup | 32 fl oz |
| 4.5 cup | 36 fl oz |
| 5 cup | 40 fl oz |
| 6 cup | 48 fl oz |
| 7 cup | 56 fl oz |
| 8 cup | 64 fl oz |
| 10 cup | 80 fl oz |
| 12 cup | 96 fl oz |
| 16 cup | 128 fl oz |
| 20 cup | 160 fl oz |
Cups vs fluid ounces: how do they compare?
The cup and the fluid ounce are two sizes within the same US customary volume system, so the real differences are in how and where each one is used.
| Attribute | Cups | Fluid ounces |
|---|---|---|
| Symbol | cup | fl oz |
| System | US customary | US customary |
| Defined as | 16 tbsp (236.59 mL) | 2 tbsp (29.57 mL) |
| One unit equals | 8 fl oz | 0.125 cup |
| Share of a US gallon | 1/16 | 1/128 |
| Typical measuring tool | Nested dry cups; 1, 2 and 4 cup liquid jugs | Jiggers, baby bottles and the ounce scale on liquid jugs |
| Where you see it | Recipes and cookbooks | Drink and bottle labels, bar recipes, baby formula |
| Imperial (UK) counterpart | 284.13 mL cup (10 imperial fl oz) | 28.41 mL imperial fluid ounce (1/160 imperial gallon) |
| Value on US nutrition labels | 240 mL | 30 mL |
5 key differences
- A cup is exactly 8 fluid ounces, so the two units convert with no rounding at all.
- Fluid ounces suit drinks and small pours, while cups suit recipe amounts from ¼ cup upward.
- The US fluid ounce (29.57 mL) is about 4.08% larger than the imperial fluid ounce (28.41 mL).
- Neither unit measures weight: an ounce on a kitchen scale is the avoirdupois ounce of 28.35 g, a separate unit of mass.
- Label rounding under FDA 21 CFR 101.9 keeps the ratio intact, since 240 mL per cup and 30 mL per fluid ounce is still 8 to 1.
Cup fractions in fluid ounces, spoons and milliliters
Recipes use thirds and eighths of a cup, which do not look neat as decimals. This chart gives each measuring-cup size in fluid ounces, in tablespoons and teaspoons for when the cup is dirty, and in milliliters. Spoon conversions are on the tablespoons to teaspoons converter.
| Cups | Fluid ounces | Tablespoons and teaspoons | Milliliters |
|---|---|---|---|
| ⅛ cup | 1 fl oz | 2 tbsp | 29.6 mL |
| ¼ cup | 2 fl oz | 4 tbsp | 59.1 mL |
| ⅓ cup | 2⅔ fl oz | 5 tbsp + 1 tsp | 78.9 mL |
| ½ cup | 4 fl oz | 8 tbsp | 118.3 mL |
| ⅔ cup | 5⅓ fl oz | 10 tbsp + 2 tsp | 157.7 mL |
| ¾ cup | 6 fl oz | 12 tbsp | 177.4 mL |
| 1 cup | 8 fl oz | 16 tbsp | 236.6 mL |
| 1½ cups | 12 fl oz | 24 tbsp | 354.9 mL |
| 2 cups | 16 fl oz | 32 tbsp | 473.2 mL |
| 4 cups | 32 fl oz | 64 tbsp | 946.4 mL |
US, metric, UK and Japanese cups in fluid ounces
A “cup” is not the same size everywhere, and the UK fluid ounce (28.41 mL) is slightly smaller than the US one (29.57 mL). Check where a recipe comes from before converting. The US nutrition-label cup is rounded to 240 mL by FDA labeling rules.
| Cup | Milliliters | US fluid ounces | Imperial fluid ounces |
|---|---|---|---|
| US customary cup | 236.59 mL | 8.00 US fl oz | 8.33 imp fl oz |
| US nutrition-label cup | 240 mL | 8.12 US fl oz | 8.45 imp fl oz |
| Metric cup (Australia, NZ, Canada) | 250 mL | 8.45 US fl oz | 8.80 imp fl oz |
| UK imperial cup (half an imperial pint) | 284.13 mL | 9.61 US fl oz | 10.00 imp fl oz |
| Japanese cup | 200 mL | 6.76 US fl oz | 7.04 imp fl oz |
| Japanese rice-cooker cup (1 gō) | 180 mL | 6.09 US fl oz | 6.34 imp fl oz |
Drinks and containers in cups and fluid ounces
Bottles, cans and cartons are labeled in fluid ounces in the US and in milliliters elsewhere. Here is how they translate into cups. Larger volumes are easier on the liters to gallons converter.
| Container | Fluid ounces | Cups | Milliliters |
|---|---|---|---|
| 12 fl oz can of soda | 12 fl oz | 1.5 cups | 355 mL |
| 500 mL water bottle | 16.91 fl oz | 2.11 cups | 500 mL |
| 20 fl oz soda bottle | 20 fl oz | 2.5 cups | 591 mL |
| 1 US pint | 16 fl oz | 2 cups | 473 mL |
| 1 US quart | 32 fl oz | 4 cups | 946 mL |
| 1 liter | 33.81 fl oz | 4.23 cups | 1,000 mL |
| Half gallon of milk | 64 fl oz | 8 cups | 1,893 mL |
| 1 US gallon | 128 fl oz | 16 cups | 3,785 mL |
Are fluid ounces and ounces by weight the same?
No: a fluid ounce is a volume of 29.57 mL, while a weight ounce is a mass of 28.35 g, so the same 8 fl oz cup weighs very different amounts depending on what is in it. Using the typical weights from our cups to grams chart:
- Water: about 237 g, or 8.36 oz by weight.
- Whole milk: about 244 g, or 8.61 oz.
- Honey: about 336 g, or 11.85 oz, because honey is much denser than water.
- All-purpose flour: about 120 g, or 4.23 oz.
- Rolled oats: about 89 g, or 3.14 oz.
So “8 ounces of chocolate chips” and “1 cup of chocolate chips” are not the same amount: a cup of chips is about 170 g, or 6 oz. As a rule, if the ingredient is a liquid and the recipe says fl oz, measure it in a cup; if it is solid, or the recipe just says oz, weigh it.
When a “cup” is not a cup
Coffee makers and some mugs use their own “cup” that is often smaller than 8 fl oz, so check the manual before scaling a coffee ratio. Drinking-water advice such as “eight glasses a day” assumes 8 fl oz glasses: 8 × 8 = 64 fl oz, which is 8 cups or about 1.9 liters.
How do you measure fluid ounces accurately?
Use a clear, spouted liquid measuring cup on a flat counter and read the ounce line at eye level, at the bottom of the curved surface (the meniscus). Looking down from above makes you under-pour. A few more habits help:
- Do not use dry cups for liquids. Dry cups are meant to be filled to the brim and leveled, which is hard with a liquid, so you tend to come up short.
- Check the fluid ounce markings. Most US jugs show cups, fl oz and mL. British jugs mark imperial fluid ounces, where a pint is 20 fl oz instead of 16.
- Coat the cup for sticky liquids. A light film of oil lets honey and syrup slide out, so you get the full measure.
Sources and further reading
The standards and references behind the numbers on this page. Links open in a new tab.
Standards and official sources
- NIST Handbook 44: Specifications, Tolerances and Other Technical RequirementsNIST
- 21 CFR 101.9: Nutrition labeling of foodCornell Law School LII
- Weights and Measures Act 1985legislation.gov.uk
Further reading
- US cupWikipedia
- Fluid ounceWikipedia
Cups to fluid ounces FAQs
Short, exact answers to what people ask most.
How many fluid ounces are in a cup?
One US cup holds exactly 8 US fluid ounces, which is about 236.59 mL. Two cups make a pint of 16 fl oz.
How many ounces is half a cup?
Half a US cup is 4 fluid ounces. A quarter cup is 2 fl oz, and three quarters of a cup is 6 fl oz.
Is 8 oz always 1 cup?
Only for fluid ounces, which measure volume. Eight ounces by weight fill 1 cup only for liquids close to water; 8 oz of flour is nearly 2 cups.
How many cups is 16 fl oz?
16 fl oz is exactly 2 US cups, or one US pint. 32 fl oz is 4 cups, which is a quart.
How many fluid ounces are in a metric cup?
A 250 mL metric cup holds 8.45 US fl oz, a little more than a US cup. In UK imperial fluid ounces it is 8.8 fl oz.
How many cups is 64 ounces of water?
64 fl oz of water is 8 US cups, or half a gallon. That is about 1.89 liters.
How many fl oz is 3 cups?
3 US cups is exactly 24 fl oz, which is 709.76 mL.
How many fluid ounces is ⅓ cup?
⅓ cup is 2⅔ fl oz, about 2.67 fl oz or 78.86 mL. It equals 5 tablespoons plus 1 teaspoon.
How many cups are in 12 fluid ounces?
12 fl oz is exactly 1½ cups, the volume of a standard US soda can.
Related conversions
NIST Handbook 44 (1 US gallon = 231 in³ = 128 US fluid ounces = 16 cups); FDA nutrition labeling rules (21 CFR 101.9) for the 240 mL label cup and 30 mL label fluid ounce; UK Weights and Measures Act 1985 for the imperial gallon, pint and fluid ounce. Last updated . How we verify our numbers.