A metric carat is exactly 200 milligrams.
Carats to Milligrams Converter — ct to mg
Convert Carat (ct) to Milligram (mg) using the exact conversion factor (1 carat = 200 milligram). See the formula, worked examples, and conversion table.
Carats to Milligrams converter
Converter
Mass/Weight Converter
Convert SI mass, imperial weight, jewelry, atomic, and astronomy mass units.
Context values
Some unit families need one extra value for a physically accurate result.
Milligram is 0.001 gram units.
Result = input x 0.0002 / 1e-6.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Carats to Milligrams
Weight conversions between Carat and Milligram come up constantly in everyday commerce, shipping, and cooking, since US packaging is usually labeled in pounds while most of the rest of the world uses kilograms. Specifically: A metric carat is exactly 200 milligrams, and milligram is 0.001 gram units.
Formula
milligrams = carats × 200
This factor comes from each unit's defined relationship to the category's base unit: 1 carat equals 0.0002 base units, and 1 milligram equals 0.000001 base units, so dividing one by the other gives the direct carat-to-milligram factor of 200.
Simple example
1 ct × 200 = 200 mg
1 carat = 200 milligrams.
Real-world example
50 ct × 200 = 10,000 mg
50 carats = 10,000 milligrams.
Conversion table
| Carat (ct) | Milligram (mg) |
|---|---|
| 1 ct | 200 mg |
| 5 ct | 1,000 mg |
| 10 ct | 2,000 mg |
| 25 ct | 5,000 mg |
| 50 ct | 10,000 mg |
| 100 ct | 20,000 mg |
Reverse conversion: Milligram to Carat
200 mg × 0.005 = 1 ct
200 milligrams = 1 carats.
carats = milligrams × 0.005
For a page dedicated to this direction, see Milligram to Carat.
Understanding the Carat (ct)
A metric carat is exactly 200 milligrams.
Understanding the Milligram (mg)
Milligram is 0.001 gram units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many milligrams are in 1 carat?
1 carat equals 200 milligrams, using the exact defined conversion factor rather than an estimate.
How do I convert carat to milligram?
Multiply the carat value by 200. The converter above does this instantly to whatever precision you set.
How do I convert milligram back to carat?
Use the reverse factor: 1 milligram equals 0.005 carats. You can also use the swap control in the converter above to flip the direction instantly.
What is a carat?
Carat (ct) is a unit of mass/weight.
What is a milligram?
Milligram (mg) is a unit of mass/weight.
Is the carat to milligram conversion exact?
Yes. Both carat and milligram are defined by fixed standards rather than physical artifacts, so the factor of 200 used above is exact to as many digits as you choose to display.