Sapphire Centre
How Does Carat Weight Affect a Sapphire?
What carat weight really means for sapphires, weight versus face-up size, price-per-carat thresholds and how to compare stones sensibly.
3 min read
Carat Weight Converter
Convert gemstone weights between carats, grams, milligrams and points. Useful for reading laboratory reports, comparing quotes and checking arithmetic on receipts.
- Carats
- 1 ct
- Grams
- 0.2 g
- Milligrams
- 200 mg
- Points
- 100
One metric carat is defined as 200 milligrams (0.2 grams); one point is one hundredth of a carat. Carat (gem weight) is not the same as karat (gold purity).
This tool performs exact unit conversions. Weight alone says little about a gemstone's value: two stones of identical weight can differ enormously in price. Carat (gem weight) is not karat (gold purity).
About this tool
Method: Fixed unit arithmetic: 1 metric carat = 200 milligrams = 0.2 grams; 1 point = 1/100 carat.
Limitations: Converts units only. It does not verify a stated weight and gives no indication of value.
Sources: GIA 4Cs: carat weight definition · Glossary: carat
Last updated: 24 July 2026. Runs entirely in your browser; nothing you enter is transmitted or stored.
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