Carats (ct) to Milligrams (mg) Converter
Enter a value to instantly convert between weight units.
1 Carat = 200 Milligram
Key Formulas
Kilogram → Pound
lb = kg × 2.20462Pound → Kilogram
kg = lb × 0.453592Gram → Ounce
oz = g × 0.035274Ounce → Gram
g = oz × 28.3495Formula
mg = ct × 200One carat equals exactly 200 milligrams — this is a definition, not an approximation. Jewelers and gemologists convert between carats and milligrams constantly: grading reports show carat weight, but jewelry manufacturing records often need metric precision in milligrams. The 200-to-1 relationship makes the math trivial.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A jeweler setting a 1-carat center stone knows it weighs 200 mg — useful for the prong design calculations.
1 ct = 200 mg
A jewelry manufacturer ordering 5 carats of small accent stones receives 1000 mg of material.
5 ct = 1000 mg
A customer asking about a half-carat diamond learns it weighs 100 mg — about the weight of a drop of water.
0.5 ct = 100 mg
A diamond grading report listing 10 carats total weight converts to 2000 mg for the certificate.
10 ct = 2000 mg