Carat to Grams Converter

Convert carat (ct) to grams (g) instantly using the standard metric carat (1 ct = 0.2 g). Includes reverse grams to carats, decimal control, jewelry-friendly presets, and a quick reference table.

Convert carats to grams

Jewelry presets:

How to use this converter

Enter the weight in carats and choose how many decimal places you would like to see. The calculator multiplies the carat value by 0.2 (1 carat = 0.2 grams). Use the jewelry presets for common gemstone sizes, then click Convert to see the precise gram weight.

Methodology

We rely on the fixed definition of the metric carat: it is exactly 0.2 grams. This means every carat measurement maps to grams through a single multiplication factor, so the engine handles all decimals deterministically.

Core equations

1 carat (ct) = 0.2 grams (g)

grams = carats × 0.2

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?

The carat weight used here is the gemstone/jewelry carat (diamond, gemstone, pearls). Gold purity "karat" (with a K) is not a weight unit.

Why is 5 carats = 1 gram?

Because 1 carat equals 0.2 grams, so 1 ÷ 0.2 = 5. That means multiply grams by 5 to reverse the operation.

Full original guide (expanded)

Why use this tool?

Unlike generic converters, this one is tuned to jewelry use cases (0.25–5 ct), forces the precise 0.2 g factor, and supports reverse conversions for appraisals, sourcing, and product specs.

Audit: Complete

Verified by Ugo Candido on 2026-01-19. Related profile and LinkedIn links are preserved from the legacy page.

Formula details

1 carat (ct) = 0.2 grams (g)
Formulas

Metric carat definition:

1 carat (ct) = 0.2 grams (g)

grams = carats × 0.2

carats = grams ÷ 0.2 = grams × 5

Citations

No citations were provided in the original legacy page.

Changelog
  • 0.1.0-draft — 2026-01-19: Initial draft (review required).
Verified by Ugo Candido Last Updated: 2026-01-19 Version 0.1.0-draft
Version 1.5.0