Convert Carats to Grains
1 carat is 3.09 gr. One carat is exactly 3.08647167059 grains.
One carat is 3.0864717 grains. To convert carats to grains, multiply by 3.0864717; to go the other way, divide by 3.0864717 or multiply by 0.32399455. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and 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 × 3.0864717
1 * 3.08647173.086 gr
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 grains? The converter and the working
- 1.Take the measurement in carats.
- 2.Multiply by 3.0864717 — that is how many grains fit in one carat.
- 3.To go back the other way, divide by 3.0864717, or multiply by 0.32399455.
Worked example: 25 carats to grains
- Formula
- ct × 3.0864717 = gr
- Arithmetic
- 25 × 3.0864717 = 77.16 gr
- Answer
- 25 ct = 77.16 gr
The factor is rounded for display; the figure above is computed from the full value.
Carats to grains conversion table
| Carats | Grains |
|---|---|
| 1 ct | 3.09 gr |
| 2 ct | 6.17 gr |
| 3 ct | 9.26 gr |
| 4 ct | 12.35 gr |
| 5 ct | 15.43 gr |
| 6 ct | 18.52 gr |
| 7 ct | 21.61 gr |
| 8 ct | 24.69 gr |
| 9 ct | 27.78 gr |
| 10 ct | 30.86 gr |
| 12 ct | 37.04 gr |
| 15 ct | 46.3 gr |
| 20 ct | 61.73 gr |
| 25 ct | 77.16 gr |
| 50 ct | 154.32 gr |
| 100 ct | 308.65 gr |
| 200 ct | 617.29 gr |
| 300 ct | 925.94 gr |
| 500 ct | 1,543.24 gr |
| 1000 ct | 3,086.47 gr |
| 2000 ct | 6,172.94 gr |
| 5000 ct | 15,432.36 gr |
| 10000 ct | 30,864.72 gr |
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 grain?
Exactly 64.79891 milligrams, the unit both the avoirdupois and troy systems are built from. Bullet weights and powder charges are still measured in it, and so are some pharmaceutical doses.
How many grains are in a carat?
One carat is 3.0864717 grains. Going the other way, one grain is 0.32399455 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 grains. Rule Calculator. https://rulecalculators.com/convert/carat-to-grain
- MLA
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- Chicago
- Rule Calculator. "Convert Carats to grains." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/carat-to-grain.
The date is when the figures on this page were last checked against their source, not the day you opened it. Add your own access date if your style needs one.
Questions people actually ask
- How many grains are in a carat?
- 3.0864717. Exactly 64.79891 milligrams, the unit both the avoirdupois and troy systems are built from. Bullet weights and powder charges are still measured in it, and so are some pharmaceutical doses.
- How do I convert grains back to carats?
- Divide by 3.0864717, or multiply by 0.32399455 — they are the same operation.
Other weight conversions
Grains to carats — the same conversion the other way.