Convert Carats to Milligrams
1 carat is 200 mg. One carat is exactly 200 milligrams.
One carat is 200 milligrams. To convert carats to milligrams, multiply by 200; to go the other way, divide by 200 or multiply by 0.005. The factor is exact rather than rounded: it follows from NIST Handbook 44. Exactly 200 milligrams, fixed by international agreement in 1907 after centuries of local carats.
Factor checked against the defining standard · How we check
- Carats × 200
1 * 200200 mg
1 carat in every weight unit
| Unit | Value | Exact factor |
|---|---|---|
| ounces | 0.00705479239 oz | × 0.00705479238992 |
| pounds | 0.0004409245244 lb | × 0.00044092452437 |
| stone | 0.00003149460888 st | × 0.0000314946088836 |
| US tons | 0.0000002204622622 ton | × 0.000000220462262185 |
| micrograms | 200,000 mcg | × 200,000 |
| milligrams | 200 mg | × 200 |
| centigrams | 20 cg | × 20 |
| grams | 0.2 g | × 0.2 |
| kilograms | 0.0002 kg | × 0.0002 |
| slugs | 0.00001370435317 slug | × 0.0000137043531714 |
| tonnes | 0.0000002 t | × 0.0000002 |
| carats (as entered) | 1 ct | — |
| troy ounces | 0.006430149314 ozt | × 0.00643014931373 |
| grains | 3.086471671 gr | × 3.08647167059 |
| long tons | 0.0000001968413055 LT | × 0.000000196841305522 |
Factors are entered by hand from NIST Handbook 44 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert carats to milligrams? The converter and the working
- 1.Take the measurement in carats.
- 2.Multiply by 200 — that is how many milligrams fit in one carat.
- 3.To go back the other way, divide by 200, or multiply by 0.005.
Worked example: 25 carats to milligrams
- Formula
- ct × 200 = mg
- Arithmetic
- 25 × 200 = 5,000 mg
- Answer
- 25 ct = 5,000 mg
The factor is exact, so this figure is exact too — only the display is rounded.
Carats to milligrams conversion table
| Carats | Milligrams |
|---|---|
| 1 ct | 200 mg |
| 2 ct | 400 mg |
| 3 ct | 600 mg |
| 4 ct | 800 mg |
| 5 ct | 1,000 mg |
| 6 ct | 1,200 mg |
| 7 ct | 1,400 mg |
| 8 ct | 1,600 mg |
| 9 ct | 1,800 mg |
| 10 ct | 2,000 mg |
| 12 ct | 2,400 mg |
| 15 ct | 3,000 mg |
| 20 ct | 4,000 mg |
| 25 ct | 5,000 mg |
| 50 ct | 10,000 mg |
| 100 ct | 20,000 mg |
| 200 ct | 40,000 mg |
| 300 ct | 60,000 mg |
| 500 ct | 100,000 mg |
| 1000 ct | 200,000 mg |
| 2000 ct | 400,000 mg |
| 5000 ct | 1,000,000 mg |
| 10000 ct | 2,000,000 mg |
What is a carat?
Exactly 200 milligrams, fixed by international agreement in 1907 after centuries of local carats. It weighs a gemstone; the karat that grades gold is a different word for a different thing — purity in twenty-fourths.
What is a milligram?
One thousandth of a gram, and exactly 1,000 micrograms. The unit almost every medicine is dosed in.
How many milligrams are in a carat?
One carat is 200 milligrams, exactly. Going the other way, one milligram is 0.005 carats. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every weight unit here
The whole group — 15 units with their symbols and the size of each one in kilograms — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a carat.
Cite this page
- APA
- Rule Calculator. (2026). Convert Carats to milligrams. Rule Calculator. https://rulecalculators.com/convert/carat-to-milligram
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- Chicago
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Questions people actually ask
- How many milligrams are in a carat?
- 200. One thousandth of a gram, and exactly 1,000 micrograms. The unit almost every medicine is dosed in.
- How do I convert milligrams back to carats?
- Divide by 200, or multiply by 0.005 — they are the same operation.
Other weight conversions
Milligrams to carats — the same conversion the other way.