Quarter Teaspoon.
That is 1/6 of a teaspoon.
Milligrams is a measure of mass, a quarter teaspoon is a measure of volume, the two forms of measurement cannot be interchanged without knowing the density of the substance, meaning you can't measure milligrams by a teaspoon or any fraction of a teaspoon.
Not enough info. What are we converting it into.
60 teaspoon
1/6th of a teaspoon but damned if I can find a measuring spoon that small.
1/2 cc is about 10% of one teaspoon.
1/8 teaspoon
15 drops equals 1/4 teaspoon.(I had the same question, and found this answer on a few different sites.)
One third
4 quarter teaspoons is a full teaspoon, or 5 grams of water.
half a teaspoon each