1 Milligram = 0.005 Carat
Milligram is a small unit of mass in metric system and mostly used in medicine, pharmacy etc. The abbreviation is "mg".
Carat is a unit of mass and used to describe the weight of diamonds, gemstones, pearls. 1 grams equals to 5 carats and 1 ounce is 141.747616 carats. It is abbreviated as "ct".