How it's calculated
tsp = mg ÷ k (k = milligrams per teaspoon of the substance)
mg = milligrams, tsp = teaspoons, k = substance-specific mg per teaspoon (from its density). Reverse: mg = tsp × k.
Common questions
Why do I need to pick an ingredient?
Milligrams measure weight and teaspoons measure volume. A teaspoon of salt weighs far more than a teaspoon of flour, so the density of the ingredient sets the answer.
How many milligrams are in a teaspoon of salt?
About 6,000 mg, since one teaspoon of table salt weighs roughly 6 grams.