A gram (g) is a unit of mass or weight that is used especially in the International system of Units and it is equal to one thousandth of a kilogram.
A milligram (mg) is also a unit of mass or weight and it is equal to one thousandth of a gram.
Formula to convert mg to g.
Since from the definition we are told that a milligram is equivalent to one thousandth of a gram, therefore we can say that;
1 milligram is equal to 0.001g.
Hence, to convert mg to g, we multiply the mg value by 0.001.
Mass in g = Mass in mg x 0.001
Convert 500 mg to g.
= 500 x 0.001
= 0.5 grams.