How US cups, spoons and fluid ounces fit together
US recipes measure by volume, in teaspoons, tablespoons, cups and fluid ounces. The sizes are fixed in NIST Handbook 44: a tablespoon is 3 teaspoons or half a fluid ounce, a measuring cup is 8 fluid ounces or half a liquid pint, 2 pints make a quart, and 4 quarts make a gallon of 231 cubic inches, which is 128 fluid ounces (NIST Handbook 44, Appendix C, 2026 edition). With the inch defined as exactly 2.54 cm, that makes a US fluid ounce 29.5735295625 ml and a cup 236.5882365 ml, the same values NIST lists rounded in its SP 811 conversion table.
Because every US measure is a whole number of teaspoons, any amount can be built from cups and spoons. The converter does that under the result. Awkward fractions come up when a recipe is halved or tripled:
| Amount | Teaspoons | Measure it as |
|---|---|---|
| 1/16 cup | 3 | 1 tbsp |
| 1/8 cup | 6 | 2 tbsp |
| 1/6 cup | 8 | 2 tbsp + 2 tsp |
| 1/3 cup | 16 | 1/3 cup, or 5 tbsp + 1 tsp |
| 3/8 cup | 18 | 1/4 cup + 2 tbsp |
| 5/8 cup | 30 | 1/2 cup + 2 tbsp |
| 2/3 cup | 32 | 2/3 cup, or 10 tbsp + 2 tsp |
| 7/8 cup | 42 | 3/4 cup + 2 tbsp |
Why a cup can be 236.6, 240 or 250 ml
Not every cup in a recipe is the same cup, and the differences add up in baking.
- US customary cup, 236.59 ml. The measuring cup of US recipes, 8 US fluid ounces.
- Nutrition label cup, 240 ml. For nutrition labeling, FDA rules say a teaspoon means 5 ml, a tablespoon 15 ml, a cup 240 ml and a fluid ounce 30 ml (21 CFR 101.9(b)(5)(viii), revised as of April 1, 2024).
- Metric cup, 250 ml. A quarter of a liter. Food Standards Australia New Zealand, for example, uses 250 ml as one cup in its work on the Australian Dietary Guidelines (FSANZ, Appendix 2).
A metric cup holds about 5.7% more than a US cup, so 3 metric cups of milk are about 3 1/6 US cups. For a single cup the gap is small, but for a cake with several cups of liquid, use the cup the recipe was written with. When a recipe gives milliliters as well, those are the safest numbers to follow.
UK pints and fluid ounces
The UK has its own imperial pint and fluid ounce, which share their names with US units but not their sizes. UK law defines the gallon as 4.54609 liters and the pint as 0.56826125 liter, with the quart a quarter of a gallon and the fluid ounce 1/20 of a pint (Weights and Measures Act 1985, Schedule 1). So a UK fluid ounce is 28.41 ml, a bit smaller than the US one, while a UK pint is 568.26 ml, a fifth larger than the 473.18 ml US pint, because it holds 20 fluid ounces instead of 16.
| Unit | US | UK imperial |
|---|---|---|
| Fluid ounce | 29.57 ml | 28.41 ml |
| Pint | 473.18 ml | 568.26 ml |
| Quart | 946.35 ml | 1,136.52 ml |
| Gallon | 3.785 l | 4.546 l |
Worked examples
A few conversions that come up again and again, worked out step by step so you can check them on paper:
- Half of 3/4 cup. 3/4 cup is 36 teaspoons, half of that is 18 teaspoons, which is 6 tablespoons or 1/4 cup plus 2 tablespoons.
- Triple 1/3 cup. 3 × 16 teaspoons is 48 teaspoons, exactly 1 cup.
- 200 ml of milk in US cups. 200 ÷ 236.59 is 0.845 cup. In measures: 3/4 cup plus 1 tablespoon plus about 1 1/2 teaspoons.
- A cup of stock from a metric recipe. 250 ml is 1.057 US cups, so 1 US cup plus 1 tablespoon is close enough for a soup.
- A UK pint of milk in US cups. 568.26 ml ÷ 236.59 ml is 2.4 cups, a little less than 2 1/2 cups.
Type any of these into the converter, with Scale this amount for the halving and tripling, and it shows the same answers along with the cups and spoons to use.
Volume is not weight
Every unit here measures volume: how much space an ingredient takes up. A fluid ounce is not an ounce on a scale, and a cup of flour weighs far less than a cup of honey. For dry ingredients by weight, use the cups to grams converter, which has weights for flour, sugar, butter and many more. To change the number of servings of a whole recipe at once, paste it into the recipe scaler, and for oven settings use the oven temperature converter.
How to use the cooking measurement converter
- 1Type the amount from your recipe. Fractions like 1/3 or 1 1/2 work.
- 2Pick the unit it is in and the unit you want. The swap button turns the conversion around.
- 3Read the result, how to measure it with US cups and spoons, and the same amount in every other unit. Use Scale this amount to halve or double it, then copy the result or a link.
Frequently asked questions
How many tablespoons are in a cup?
16. In US measures a tablespoon is half a fluid ounce and a cup is 8 fluid ounces, so one cup holds 16 tablespoons or 48 teaspoons. Half a cup is 8 tablespoons and a quarter cup is 4.
How many milliliters are in a cup?
A US customary cup is 236.59 ml. Nutrition labels in the US use a cup of 240 ml, as set by the FDA rules for nutrition labeling. A metric cup is 250 ml. The converter has all three, so pick the cup your recipe means.
How many teaspoons are in a tablespoon?
Three. That holds for US measuring spoons, and also for the 5 ml teaspoon and 15 ml tablespoon that US nutrition labels use.
Is a UK pint the same as a US pint?
No. A UK pint is 568.26 ml and holds 20 UK fluid ounces. A US pint is 473.18 ml and holds 16 US fluid ounces. A UK fluid ounce is also a little smaller than a US one: 28.41 ml against 29.57 ml.
How do I measure 1/3 cup without a 1/3 cup measure?
Use 5 tablespoons plus 1 teaspoon. A cup is 48 teaspoons, so a third of a cup is 16 teaspoons, which is 5 tablespoons (15 teaspoons) and 1 teaspoon more.
What is half of 1/3 cup?
2 tablespoons plus 2 teaspoons. Half of 16 teaspoons is 8 teaspoons, which is 2 tablespoons and 2 teaspoons. Enter 1/3 cup and use Scale this amount with ½× to see it.
Are fluid ounces and ounces the same?
No. A fluid ounce measures volume, an ounce measures weight. Cups, spoons and fluid ounces tell you how much space something takes up. For flour, sugar or butter by weight, use the cups to grams converter.