Convert Milligrams to Carats
1 milligram (mg) equals 0.005 carats (ct).
1 mg = 0.005 ct
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk milligram to carat converter to paste a column from Excel.
How to Convert Milligram to Carat
- 1 mg = 0.005 ct
- 1 ct = 200 mg
- Example: convert 15 mg to ct: 15 mg = 15 × 0.005 ct = 0.075 ct
Formula
ct = mg ÷ 200
Derivation from SI units:
- 1 mg = 10⁻⁶ kg = 10⁻³ g
- 1 ct = 200 mg (metric carat, exact)
- 1 mg = 0.000001 kg ÷ 0.0002 kg per ct = 0.005 ct
Both units are defined exactly, so the factor is exact. Milligram definition: milligram; Carat definition: carat.
Worked examples
- A reading of 20 mg converts to 0.1 ct.
20 mg × 0.005 = 0.1 ct - A value of 250 mg is 1.25 ct.
250 mg × 0.005 = 1.25 ct
Milligram to Carat conversion table
| Milligrams (mg) | Carats (ct) |
|---|---|
| 0.1 mg | 0.0005 ct |
| 0.5 mg | 0.0025 ct |
| 1 mg | 0.005 ct |
| 2 mg | 0.01 ct |
| 5 mg | 0.025 ct |
| 10 mg | 0.05 ct |
| 20 mg | 0.1 ct |
| 25 mg | 0.125 ct |
| 50 mg | 0.25 ct |
| 65 mg | 0.325 ct |
| 81 mg | 0.405 ct |
| 100 mg | 0.5 ct |
| 200 mg | 1 ct |
| 250 mg | 1.25 ct |
| 325 mg | 1.625 ct |
| 400 mg | 2 ct |
| 500 mg | 2.5 ct |
| 1000 mg | 5 ct |
| 2000 mg | 10 ct |
| 5000 mg | 25 ct |
Where it's used
Milligrams are used for medication doses (e.g. 500 mg tablets), while carats appear in diamonds and gemstones. Both measure mass (commonly called weight), so the conversion is a fixed factor.
Milligram to other weight and mass units
| Conversion | 1 mg equals |
|---|---|
| milligram to kilogram | 0.000001 kg |
| milligram to gram | 0.001 g |
| milligram to microgram | 1000 µg |
| milligram to metric ton | 1 × 10⁻⁹ t |
| milligram to pound | 0.000002204622622 lb |
| milligram to ounce | 0.00003527396195 oz |
| milligram to stone | 1.574730444 × 10⁻⁷ st |
| milligram to short ton | 1.102311311 × 10⁻⁹ ton (US) |
| milligram to long ton | 9.842065276 × 10⁻¹⁰ ton (UK) |
| milligram to grain | 0.01543235835 gr |
| milligram to troy ounce | 0.00003215074657 oz t |
| milligram to carat | 0.005 ct |
Frequently asked questions
How many carats are in 1 milligram?
1 mg = 0.005 ct.
How do I convert milligrams to carats?
Multiply the value in mg by 0.005, or divide it by 200. For example, 15 mg × 0.005 = 0.075 ct.
Is the mg to ct conversion exact?
Yes. Both units are defined exactly, and 1 mg is exactly 0.005 ct.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
- 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".
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 Milligrams to Carats. Retrieved October 17, 2026, from https://scientificconverters.com/mass/milligrams-to-carats/
IEEE
Scientific Converters, "Convert Milligrams to Carats," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/mass/milligrams-to-carats/