Cooking Measurement Converter (cups, tbsp, tsp, mL)

Understanding the cooking measurement converter — concept and principle

Recipes from different countries use cups and spoons of different sizes. A US cup, a metric cup and a Korean or Japanese cup are not the same, and the gap is big enough to change a cake. This converter switches volumes between US cups, tablespoons, teaspoons and fluid ounces, metric cups and spoons, the 200 mL Korean/Japanese cup and milliliters.

1 US cup = 236.588 mL, slightly more than a Korean cup and less than a metric cup.

How it is calculated

Each unit is converted to milliliters and then divided by the target unit:

US cup = 236.5882365 mL = 8 US fl oz = 16 US tbsp = 48 US tsp
US tbsp = 14.78676478 mL; US tsp = 4.928921594 mL; US fl oz = 29.57352956 mL
Metric cup = 250 mL; metric tbsp = 15 mL; metric tsp = 5 mL
Korean/Japanese cup = 200 mL

result = value × (mL per "from" unit) ÷ (mL per "to" unit).

The principle

US kitchen units come from the US customary gallon of 231 cubic inches: one gallon = 4 quarts = 16 cups, and each cup splits into halves down to the teaspoon. Because the inch is defined as exactly 2.54 cm, these units have exact metric values. Metric countries later rounded the cup and spoons to convenient milliliter figures, and Korea and Japan adopted a 200 mL cup, closer to a rice-bowl or drinking cup.

Worked example

Default: 1 US cup to milliliters.

1 US cup = 236.5882365 mL by definition.
So 1 × 236.5882365 = 236.5882365 mL.
In other units: 0.946 metric cups (236.588 ÷ 250), 1.183 Korean/Japanese cups (236.588 ÷ 200), 16 US tbsp, 48 US tsp, 15.77 metric tbsp and 8 US fl oz.

How to read the result

For most cooking, rounding a US cup to 240 mL and a tablespoon to 15 mL is fine; US nutrition labels themselves use a 240 mL cup. Baking is more sensitive: replacing a 250 mL cup with a 200 mL Korean cup in a recipe means using 20% less of every ingredient. Australian recipes use a 20 mL tablespoon, so 4 Australian tablespoons (80 mL) equal about 5.4 US tablespoons.

Common mistakes

Converting cups of flour or sugar to grams with the water factor; a cup of flour weighs much less than a cup of water, and the weight also depends on how it is scooped.
Using a Korean 200 mL measuring cup for a US recipe without scaling.
Confusing US fluid ounces (29.57 mL) with UK fluid ounces (28.41 mL) or with ounces of weight.
Using table cutlery as measuring spoons; their volume varies widely.

Keep in mind: These are volume conversions. For dry ingredients, weights in grams depend on the ingredient and packing, so a kitchen scale and the recipe's own gram figures are more reliable.

FAQ

Frequently asked questions

How many mL are in a cup?

US cup 236.59 mL, metric cup 250 mL, Korean and Japanese cup 200 mL.

How many teaspoons are in a tablespoon?

Three, in both US and metric systems (15 mL = 3 × 5 mL).

How many tablespoons are in a quarter cup?

Four US tablespoons.

Sources: NIST Handbook 44, Appendix C – General Tables of Units of Measurement · NIST Special Publication 811 (2008), Appendix B

Checked 8 Nov 2026. Factors from the SI Brochure (BIPM, 9th ed.) and NIST Special Publication 811 (2008), Appendix B.