Home › Unit Conversion › Carats to Grams

Carats to Grams (ct to g)

Convert carats to grams: 1 ct = 0.2 g. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

Formula

1 ct = 0.2 g

grams = carats × 0.2 — reverse: carats = grams × 5

The factor is derived from the SI definitions of both units (base unit: kg) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.

Worked examples

5 ct = 1 g
12.5 ct = 2.5 g
100 ct = 20 g

Carats to grams conversion table

Carats (ct)	Grams (g)
1	0.2
2	0.4
3	0.6
4	0.8
5	1
6	1.2
7	1.4
8	1.6
9	1.8
10	2
15	3
20	4
25	5
30	6
40	8
50	10
75	15
100	20
200	40
250	50
500	100
1000	200

FAQ

How many grams are in one carat?

1 ct = 0.2 g. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

What is the formula to convert carats to grams?

Multiply the value in carats by 0.2: grams = carats × 0.2. For example, 5 ct = 1 g.

How do I convert grams back to carats?

Multiply by the inverse factor 5 (carats = grams × 5), or use the grams-to-carats page.

Related conversions

Grams to carats (reverse)
Mass / Weight Converter — all mass units in one tool
Kilograms to Pounds
Pounds to Kilograms
Grams to Ounces
Ounces to Grams
Kilograms to Stone
Stone to Kilograms
Pounds to Ounces
Ounces to Pounds

Machine access

API: GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=ct&to_unit=g
MCP: server https://tttkmbb.com/mcp, tool convert_units with {"value":5,"from_unit":"ct","to_unit":"g"}
Markdown: https://tttkmbb.com/conversion/carats-to-grams.md · JSON: https://tttkmbb.com/conversion/carats-to-grams.json (add ?value= for a result) · Units: /api/v1/units?quantity=mass
OpenAPI operationId: convert_units. Freshness: static. Authentication: none.