Carat to Grams Converter

Convert gemstone or jewelry weights from carats (ct) to grams (g) using the standard metric carat where 1 ct = 0.2 g. Includes reverse grams → carats for appraisals, sourcing, and e-commerce product pages.

Convert weight

Jewelry presets:

Result

Grams:

Factor used: 1 ct = 0.2 g

Reverse (g → ct)

Carat to grams formula

The modern metric carat used in jewelry is defined as exactly 0.2 grams:

1 carat (ct) = 0.2 grams (g)

So to convert:

grams = carats × 0.2

Example: a 1.25 ct diamond × 0.2 = 0.25 g.

To go the other way:

carats = grams ÷ 0.2 = grams × 5

Quick reference table

Carats (ct)Grams (g)
0.25 ct0.05 g
0.50 ct0.10 g
0.75 ct0.15 g
1.00 ct0.20 g
1.50 ct0.30 g
2.00 ct0.40 g
5.00 ct1.00 g

FAQ

Is this for gold or diamonds?

Carat as 0.2 g is the gemstone/jewelry carat — typically for diamonds, gemstones, and pearls. Gold purity “karat” (with a K) is different and not a weight unit.

Why is 5 carats = 1 gram?

Because 1 carat is 0.2 g, so 1 ÷ 0.2 = 5. That’s a handy rule to remember: 5 ct = 1 g.