Tinker 
How to use it
Enter the amount from your recipe and pick the unit it uses. Then choose the unit you want. The converter shows the result, the volume in millilitres and the same amount in several common units. Write fractions as decimals: 1/3 cup is 0.333 and 3/4 cup is 0.75.
The formula
Every unit is defined by an exact number of millilitres. The calculator multiplies your amount by the size of the starting unit to get millilitres. It then divides by the size of the target unit.
These are the standard values. A US cup is 236.5882365 mL, a US tablespoon is 14.787 mL and a US teaspoon is 4.929 mL. A metric cup is 250 mL, a metric tablespoon is 15 mL and a metric teaspoon is 5 mL. An imperial fluid ounce is 28.413 mL. Results are rounded to 4 decimal places.
Worked example
A US recipe calls for 2 cups of milk and your jug is marked in millilitres. 2 × 236.5882365 = 473.1765 mL, which is about 475 mL in practice. Going the other way, 1 litre ÷ 236.5882365 = 4.2268 US cups.
Practical tips
Check where your recipe comes from. US, UK and Australian measures differ slightly. An Australian tablespoon is 20 mL, so convert it as 4 metric teaspoons.
This tool converts volume only. Converting cups to grams depends on the ingredient's density, so weigh flour and sugar if you need precision.
Frequently asked questions
How many tablespoons are in a cup?
A US cup holds exactly 16 US tablespoons, or 48 teaspoons.
Is a US cup the same as a metric cup?
No. A US cup is about 236.6 mL and a metric cup is 250 mL, roughly 5.7% larger. For most recipes the difference does not matter much.
Are US and imperial fluid ounces different?
Yes. A US fluid ounce is 29.57 mL and an imperial fluid ounce is 28.41 mL. A US pint has 16 fl oz, while an imperial pint has 20 imperial fl oz (568 mL).
Can I convert cups to grams here?
No. Grams measure weight, so the conversion depends on the ingredient. A cup of flour weighs much less than a cup of honey.