Convert Carats to Kilograms
1 carat (ct) equals 0.0002 kilograms (kg).
1 ct = 0.0002 kg
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk carat to kilogram converter to paste a column from Excel.
How to Convert Carat to Kilogram
- 1 ct = 0.0002 kg
- 1 kg = 5000 ct
- Example: convert 15 ct to kg: 15 ct = 15 × 0.0002 kg = 0.003 kg
Formula
kg = ct ÷ 5000
Derivation from SI units:
- 1 ct = 200 mg (metric carat, exact)
- SI base unit, fixed by the Planck constant h = 6.626 070 15 × 10⁻³⁴ J·s
Both units are defined exactly, so the factor is exact. Carat definition: carat; Kilogram definition: kilogram.
Worked examples
- A reading of 0.75 ct converts to 0.00015 kg.
0.75 ct × 0.0002 = 0.00015 kg - A value of 3 ct is 0.0006 kg.
3 ct × 0.0002 = 0.0006 kg
Carat to Kilogram conversion table
| Carats (ct) | Kilograms (kg) |
|---|---|
| 0.1 ct | 0.00002 kg |
| 0.25 ct | 0.00005 kg |
| 0.5 ct | 0.0001 kg |
| 0.75 ct | 0.00015 kg |
| 1 ct | 0.0002 kg |
| 1.5 ct | 0.0003 kg |
| 2 ct | 0.0004 kg |
| 3 ct | 0.0006 kg |
| 5 ct | 0.001 kg |
| 10 ct | 0.002 kg |
| 100 ct | 0.02 kg |
Where it's used
Carats are used for diamonds and gemstones, while kilograms appear in body weight and food packaging. Both measure mass (commonly called weight), so the conversion is a fixed factor.
Carat to other weight and mass units
| Conversion | 1 ct equals |
|---|---|
| carat to kilogram | 0.0002 kg |
| carat to gram | 0.2 g |
| carat to milligram | 200 mg |
| carat to microgram | 200000 µg |
| carat to metric ton | 2 × 10⁻⁷ t |
| carat to pound | 0.0004409245244 lb |
| carat to ounce | 0.00705479239 oz |
| carat to stone | 0.00003149460888 st |
| carat to short ton | 2.204622622 × 10⁻⁷ ton (US) |
| carat to long ton | 1.968413055 × 10⁻⁷ ton (UK) |
| carat to grain | 3.086471671 gr |
| carat to troy ounce | 0.006430149314 oz t |
Frequently asked questions
How many kilograms are in 1 carat?
1 ct = 0.0002 kg.
How do I convert carats to kilograms?
Multiply the value in ct by 0.0002, or divide it by 5000. For example, 15 ct × 0.0002 = 0.003 kg.
Is the ct to kg conversion exact?
Yes. Both units are defined exactly, and 1 ct is exactly 0.0002 kg.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "carat, metric".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Section 2.3.1, base unit definitions.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Carats to Kilograms. Retrieved October 17, 2026, from https://scientificconverters.com/mass/carats-to-kilograms/
IEEE
Scientific Converters, "Convert Carats to Kilograms," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/mass/carats-to-kilograms/