a milligram is one one-thousandth of a gram which measures mass and a milliter is one one-thousandth of a liter which measures volume so this question cannot be answered.
Here is a link of another question. :) http://wiki.answers.com/Q/How_many_milligrams_equal_1_milliliter or you could just type "How many milligrams equal 1 milliliter?"
One milliliter is equal to one gram (1 mL= 1 g), and there are 1,000 milligrams in a liter, so 3 mL is equal to 3,000 milligrams and 100 mg is equal to .1 mL.
Milligrams versus millilitersOne milliliter of water weighs one gram. There are 1000 milligrams in one gram.One milliliter of other substances will weigh more or less, depending upon their densities. A millilter of gasoline, for example, weighs less, and a milliliter of mercury weighs more -- WAY more. (No pun intended.)Milligram is a unit of mass; milliliter is a unit of volume. You can't directly convert the two. If you know the density of a substance, you can say, for example, "1 milliliter of water has a mass of 1 gram (1000 milligrams)", or "1 milliliter of lead has a mass of about 11 gram".
There are 453,592.37 milligrams in one pound.
One milliliter is equal to 0.0002641721 gallons.
One.
There are 50 grams in one milliliter and 1000 milligrams in one liter, so there are 50,000 milligrams in 50 grams.
One liter of water weighs exactly one kilogram. (This only true of water, oil, for example, weighs less.) There are 1000 ml (milliliters) in one liter, so one milliliter weighs one gram (not milligram!) and one gram is 1000 milligrams; therefore one milliliter is 1000 milligrams. There are then 0.07 milliliters in 70 milligrams.
One hundred milligrams does not equal ten milliliters. One thousand milligrams equals one gram, one gram is equal to one milliliter.
One kilogram is equal to 1000000 milligrams. Therefore, 89 milligrams is equal to 89/1000000 = 0.000089 kilograms.
One kilogram is equal to 1000000 milligrams. Therefore, 263 milligrams is equal to 263/1000000 = 0.000263 kilograms.
I think what you mean to ask is how many milliliters (ml) are in a teaspoon, there are 5ml per teaspoon. Milligrams refers to the concentration of the medication as in how many milligrams per milliliter and that will vary from medication to medication