Convert carats to grams

1 ct=0.2g

Use the converter below to change any carats value into grams instantly — with formula, conversion table, and real-world examples.

You have

Equals

0.2

Conversion formula

Forward

grams = carats × 0.2

Reverse

carats = grams × 5

Example: 10 ct × 0.2 = 2 g.

About both units

From

Carat

The metric carat equals 200 milligrams exactly. It is the standard unit for gemstone weight — diamonds, rubies, sapphires and emeralds are sold by the carat. Do not confuse with the purity carat (karat) used for gold (24K = pure gold).

Real-world: A 1-carat diamond weighs 200 mg and is typically 6.5 mm across. The Hope Diamond is 45.52 carats (9.1 g).

Read full carat reference →

Gram

The gram equals one thousandth of a kilogram. It is the standard unit in European cooking, pharmaceuticals and jewellery. An A4 sheet of 80 g/m² paper weighs about 5 g; a regular chicken egg is around 60 g. The word "gram" comes from the Greek "gramma", a small weight.

Real-world: A chicken egg weighs about 60 g. A standard bar of chocolate is 100 g. A euro coin weighs 7.5 g.

Read full gram reference →

Carat to Gram conversion table

Common carats to grams values for quick reference.

Carat (ct)	Gram (g)
1 ct	0.2 g
5 ct	1 g
10 ct	2 g
25 ct	5 g
50 ct	10 g
100 ct	20 g
250 ct	50 g
500 ct	100 g
1,000 ct	200 g
5,000 ct	1,000 g

Tips & common mistakes

Quick tips

1 carat = 200 mg = 0.2 g exactly since 1907.
Carat (gem weight) and karat (gold purity, 24 K = pure) are different words with different meanings.
A carat is divided into 100 points; a 0.25 ct diamond is called a "25-pointer".

Avoid these

Confusing carat (mass) with karat (gold purity).
Assuming a 2-carat diamond is twice the physical size of a 1-carat — volume scales with cube root of mass.
Using "karat" on gemstone certificates — international standard is "carat" spelled with a C.

Frequently asked questions

How many grams in a carat?

One carat equals 0.2 grams.

How do I convert carats to grams?

Multiply the carat value by 0.2 to get the equivalent in grams.

What is 100 carats in grams?

100 carats equals 20 grams.

Is a carat bigger than a gram?

No. 1 carat equals 0.2 grams, so one carat is smaller.

How to convert carats to grams without a calculator?

Multiply by 0.2 for a quick estimate; use a calculator for precise results.

Related weight conversions

📊 See full comparison matrix →

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