Convert Carats to Grams
1 carat is 0.2 g. One carat is exactly 0.2 grams.
One carat is 0.2 grams. To convert carats to grams, multiply by 0.2; to go the other way, divide by 0.2 or multiply by 5. 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 × 0.2
1 * 0.20.2 g
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 grams? The converter and the working
- 1.Take the measurement in carats.
- 2.Multiply by 0.2 — that is how many grams fit in one carat.
- 3.To go back the other way, divide by 0.2, or multiply by 5.
Worked example: 25 carats to grams
- Formula
- ct × 0.2 = g
- Arithmetic
- 25 × 0.2 = 5 g
- Answer
- 25 ct = 5 g
The factor is exact, so this figure is exact too — only the display is rounded.
Carats to grams conversion table
| Carats | Grams |
|---|---|
| 1 ct | 0.2 g |
| 2 ct | 0.4 g |
| 3 ct | 0.6 g |
| 4 ct | 0.8 g |
| 5 ct | 1 g |
| 6 ct | 1.2 g |
| 7 ct | 1.4 g |
| 8 ct | 1.6 g |
| 9 ct | 1.8 g |
| 10 ct | 2 g |
| 12 ct | 2.4 g |
| 15 ct | 3 g |
| 20 ct | 4 g |
| 25 ct | 5 g |
| 50 ct | 10 g |
| 100 ct | 20 g |
| 200 ct | 40 g |
| 300 ct | 60 g |
| 500 ct | 100 g |
| 1000 ct | 200 g |
| 2000 ct | 400 g |
| 5000 ct | 1,000 g |
| 10000 ct | 2,000 g |
A carat weighs the stone; a karat grades the gold
The carat is exactly 200 milligrams and measures the mass of a gemstone. The karat, spelled with a k in American use, measures the purity of gold in twenty-fourths — 18 karat is 18 parts gold in 24. They are different words for different quantities that sound identical out loud, and a jeweller quoting "22" means one or the other depending on what is in their hand.
NIST Handbook 44, Appendix C — general tables of units of measurement
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 gram?
One thousandth of a kilogram, and the unit nutrition labels use worldwide.
How many grams are in a carat?
One carat is 0.2 grams, exactly. Going the other way, one gram is 5 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.
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- APA
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- Chicago
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Questions people actually ask
- How many grams are in a carat?
- 0.2. One thousandth of a kilogram, and the unit nutrition labels use worldwide.
- How do I convert grams back to carats?
- Divide by 0.2, or multiply by 5 — they are the same operation.
Other weight conversions
Grams to carats — the same conversion the other way.