Milligrams (mg) to Carats (ct) Converter
Enter a value to instantly convert between weight units.
1 Milligram = 0.005 Carat
Key Formulas
Kilogram → Pound
lb = kg × 2.20462Pound → Kilogram
kg = lb × 0.453592Gram → Ounce
oz = g × 0.035274Ounce → Gram
g = oz × 28.3495Formula
ct = mg × 0.005A carat is exactly 200 milligrams, so converting from mg to carats means dividing by 200 or multiplying by 0.005. This is a common conversion in the gemstone and jewelry industry — gemologists weigh diamonds and precious stones in carats, but laboratory scales often display milligrams. Converting between them is daily work for jewelers and gemologists.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
A gemologist weighing a 200 mg diamond knows it's exactly 1 carat — useful for quick reference.
200 mg = 1 ct
A jewelry designer measuring 500 mg of a small gemstone notes it as 2.5 carats for the design spec.
500 mg = 2.5 ct
A diamond grading report showing 100 mg weight records 0.5 carats — a half-carat diamond.
100 mg = 0.5 ct
A jewelry manufacturer weighing 1 gram (1000 mg) of melee diamonds reports 5 carats for inventory.
1000 mg = 5 ct