Milligram (mg) and decigram (dg) are both units of mass. 1 dg equals 10 mg. To convert mg to dg, divide the mg value by 10. For example, to convert 20 mg to dg, divide 20 by 10, which equals 2 dg. This conversion is used in various fields such as science, medicine, and industry, to ensure accurate measurements and precise dosing.