How Many Milligrams in a Teaspoon?

Take the weight of one teaspoon of the food in grams and multiply it by 1,000. Then multiply by the number of teaspoons. The formula above runs these steps for water, and the converter runs them for the other foods on its list.

USDA puts a level teaspoon of active dry yeast at 4 g, which is 4,000 mg. So 1/2 tsp of yeast weighs about 2,000 mg, and 3/4 tsp about 3,000 mg.

Past a few teaspoons, grams are the easier unit to read. The teaspoons to grams page covers those amounts.

Cooks in the UK, Australia, Canada and New Zealand measure with a metric teaspoon of 5 ml. Filled with water, it weighs a round 5,000 mg. Half a metric teaspoon holds 2,500 mg of water, and a quarter teaspoon 1,250 mg.

The US teaspoon holds slightly less, so its milligram figures come out a little lower for every food. The size table below shows both spoons side by side.

Milligrams measure weight, so a teaspoon of a light, fluffy powder holds fewer of them than a teaspoon of something dense. A level teaspoon of powdered (icing) sugar weighs about 2,500 mg, while the same spoon of dry yeast weighs 4,000 mg.

How you fill the spoon matters too. A heaped or packed teaspoon can hold far more than a level one, so sweep the top flat for figures that match this page.

When a label says a teaspoon contains a certain number of milligrams of something, it describes one ingredient mixed into the product. The spoonful as a whole weighs much more than that figure.

Use the label's number for that ingredient, and use this converter only for the weight of the full spoonful. The two answers measure different things, so neither can replace the other.