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Carats to Grams Converter

Convert carats to grams and grams to carats instantly. Essential converter for gemstones and precious stones.

ct

Grams

0.5

g

2.5 ct = 0.5 g

g = ct × 0.2

How to Convert Carats to Grams

Multiply the carat value by 0.2. The metric carat was standardized in 1907 as exactly 200 milligrams (0.2 grams). This is one of the few unit conversions that is perfectly exact with no rounding involved.

Conversion Formula

  • Carats to Grams: g = ct × 0.2
  • Grams to Carats: ct = g ÷ 0.2

Common Conversions

CaratsGrams
0.250.0500
0.50.1000
0.750.1500
20.4000
3.50.7000
51.0000
153.0000

Related

FAQ

How many grams are in a carat?

One carat equals exactly 0.2 grams (200 milligrams).

What is the difference between a carat and a karat?

A carat (ct) measures gemstone weight (0.2 grams). A karat (K or kt) measures gold purity on a scale of 24 parts. They are completely different units despite the similar spelling.

Why do jewelers use carats instead of grams?

The carat originated from the carob seed, which was historically used as a balance weight due to its remarkably consistent mass. It was standardized to exactly 0.2 grams in 1907.

How much does a typical engagement ring diamond weigh in grams?

A typical engagement ring diamond ranges from 0.5 to 1.5 carats, which is 0.1 to 0.3 grams. A 1-carat diamond weighs exactly 0.2 grams.