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Convert Carat to Milligram (ct to mg) instantly with accurate, readable results.
Use our Mass Unit Converter to convert between grams, kilograms, pounds, ounces, and other weight units instantly. Designed for cooking, science, fitness, and engineering needs, this unit conversion tool offers accurate results between metric and imperial systems. Whether you’re tracking body weight, measuring ingredients, or handling heavy machinery, our mass unit conversion calculator has you covered.
Carat (ct) — a metric unit of mass for gemstones
It is defined as exactly 200 milligrams, or one fifth of a gram. Used worldwide for measuring diamonds, gemstones, pearls, and other jewels; it should not be confused with karat, which measures gold purity.
- Symbol: ct
- System: Non-SI metric unit for mass; used with SI
- Exact relations: 1 ct = 200 mg = 0.2 g = 0.0002 kg
- Imperial equivalents (derived from 1 lb = 0.45359237 kg exactly): 1 ct ≈ 0.00705479 oz ≈ 0.000440925 lb
- Typical examples: a small diamond ~0.25 ct; an engagement-ring diamond ~1 ct; large gemstones may be several ct.
Milligram (mg) — a small SI unit of mass
It is defined as one thousandth of a gram, or one millionth of a kilogram, the SI base unit for mass. Used worldwide for measuring very small masses in medicine, nutrition, chemistry, laboratory work, supplements, and precise product labeling.
- Symbol: mg
- System: SI unit for mass; decimal submultiple of the kilogram
- Exact relations: 1 mg = 0.001 g = 0.000001 kg = 1000 µg
- Imperial equivalents (derived from 1 lb = 0.45359237 kg exactly): 1 mg ≈ 0.000035274 oz ≈ 0.00000220462 lb
- Typical examples: a medicine dose ~200 mg; a vitamin tablet ~500 mg; a small grain of salt less than 1 mg.