Convert Carats to Kilograms

Convert Carats (ct) to Kilograms (kg) instantly and accurately.

Carats (ct)
Kilograms (kg)

Conversion Formula

kg = ct × 0.0002

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 Kilograms

The kilogram (kg) is the SI base unit of mass - the fundamental unit from which all other mass measurements in the metric system are derived. Since 2019 it has been defined by fixing the Planck constant h to exactly 6.62607015 × 10⁻³⁴ J·s, replacing the 130-year-old International Prototype Kilogram (a platinum-iridium cylinder kept in Sèvres, France). The kilogram governs daily life worldwide: body weight in most countries, grocery shopping, luggage allowances, postal rates, freight pricing, and ingredient quantities in cooking all reference kilograms.

Quick Reference Table

Carats (ct)Kilograms (kg)
1 ct0.0002 kg
2 ct0.0004 kg
5 ct0.001 kg
10 ct0.002 kg
25 ct0.005 kg
50 ct0.01 kg
100 ct0.02 kg

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