How many mL in a teaspoon?

1 US teaspoon = 4.929 mL. Medical teaspoons are often defined as exactly 5 mL for dosing convenience.

Is a medical teaspoon 5 mL?

For medication purposes, yes — the World Health Organization and most pharmacies standardize 1 teaspoon = 5 mL. The culinary teaspoon is 4.929 mL.

3 US teaspoons = 1 US tablespoon. So ½ tablespoon = 1.5 teaspoons.

1 US teaspoon = 4.929 mL. Multiply teaspoons by 4.929 to convert. Example: 5 tsp × 4.929 = 24.64 mL.

mL = teaspoons × 4.929

Worked example

A medicine label says take 2 teaspoons. Convert: 2 × 4.929 = 9.86 mL.

US Teaspoon (tsp)

The US teaspoon (tsp) = ⅓ US tablespoon = 4.929 mL. Standard unit for spices, baking powder, medicine, and flavouring.

Milliliter (mL)

The milliliter (mL) is 1/1000 of a liter, the standard metric unit for small liquid volumes in cooking and medicine.