Convert Carats to Milligrams

Convert Carats (ct) to Milligrams (mg) instantly and accurately.

Carats (ct)
Milligrams (mg)

Conversion Formula

mg = ct × 200

About Carats

A metric carat (ct or CD) is exactly 200 milligrams (0.2 g), the universal standard for weighing gemstones. Established internationally in 1907, it replaced fractionally different regional carat weights previously used in different countries. The total weight of a diamond or colored gemstone is always expressed in carats: a 1.00 ct diamond of excellent cut and color can command over $5,000. The Cullinan diamond, the largest gem-quality rough diamond ever found, weighed 3,106.75 carats.

About Milligrams

A milligram (mg) is one thousandth of a gram (10⁻³ g). It is the primary unit for pharmaceutical dosing: aspirin tablets are typically 500 mg, ibuprofen 200-400 mg, and melatonin supplements 0.5-10 mg. Precious metal assay results and alloy compositions are specified in milligrams per kilogram (mg/kg = ppm). Nutritional labels worldwide list mineral content in milligrams - the recommended daily intake of iron is 8-18 mg, calcium 1000 mg, and sodium under 2300 mg. A grain of rice weighs about 25-30 mg, and a medium eyelash approximately 0.1 mg.

Quick Reference Table

Carats (ct)Milligrams (mg)
1 ct200 mg
2 ct400 mg
5 ct1000 mg
10 ct2000 mg
25 ct5000 mg
50 ct10000 mg
100 ct20000 mg

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