Grains to Carats (gr to ct) Converter

How to convert grains to carats

Formulact = gr × 0.32399455

Multiply the value in grains by 0.32399455. To go the other way, multiply by 3.086471671 (or divide by 0.32399455).

A grain is smaller than a carat: it takes 3.086471671 grains to make one carat.

Worked examples

1 grain1 gr × 0.32399455 = 0.32399455 ct
5 grains5 gr × 0.32399455 = 1.61997275 ct
10 grains10 gr × 0.32399455 = 3.2399455 ct
20 grains20 gr × 0.32399455 = 6.479891 ct
100 grains100 gr × 0.32399455 = 32.399455 ct

Grains to carats conversion table

Values are calculated by the conversion engine and rounded to 8 significant figures.

Grains to carats: 0.1–10 gr
Grains (gr)	Carats (ct)
0.1 gr	0.032399455 ct
0.25 gr	0.080998638 ct
0.5 gr	0.16199728 ct
1 gr	0.32399455 ct
2 gr	0.6479891 ct
3 gr	0.97198365 ct
4 gr	1.2959782 ct
5 gr	1.6199728 ct
6 gr	1.9439673 ct
7 gr	2.2679619 ct
8 gr	2.5919564 ct
9 gr	2.915951 ct
10 gr	3.2399455 ct

Grains to carats: 12–1,000 gr
Grains (gr)	Carats (ct)
12 gr	3.8879346 ct
15 gr	4.8599183 ct
20 gr	6.479891 ct
25 gr	8.0998638 ct
30 gr	9.7198365 ct
40 gr	12.959782 ct
50 gr	16.199728 ct
75 gr	24.299591 ct
100 gr	32.399455 ct
250 gr	80.998638 ct
500 gr	161.99728 ct
1,000 gr	323.99455 ct

About the units

Grain (gr)

Exactly 64.79891 mg; 7,000 grains make a pound. Used for bullets, arrows and some medicines. One grain equals 0.00006479891 kilograms (kg).

Carat (ct)

The metric carat is exactly 200 mg and is used to weigh gemstones. (Karat, a gold-purity scale, is a different thing.) One carat equals 0.0002 kilograms (kg).

Frequently asked questions

How many carats are in one grain?

There are 0.32399455 carats in one grain, and this value is exact by definition.

How do I convert grains to carats?

Multiply the number of grains by 0.32399455. For example, 10 gr × 0.32399455 = 3.2399455 ct.

How many grains are in one carat?

One carat equals 3.086471671 grains. That is the reverse factor, 1 ÷ 0.32399455.

What is 10 grains in carats?

10 gr = 3.2399455 ct.

Is this gr to ct converter accurate?

Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.

Grains to Carats Converter