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Convert Carats to Centigrams

1 carat is 20 cg. One carat is exactly 20 centigrams.

One carat is 20 centigrams. To convert carats to centigrams, multiply by 20; to go the other way, divide by 20 or multiply by 0.05. The factor is exact rather than rounded: it follows from NIST Handbook 44. Exactly 200 milligrams, fixed by international agreement in 1907 after centuries of local carats.

Factor checked against the defining standard · How we check

Centigrams
20 cg
Carats × 20
1 * 2020 cg

1 carat in every weight unit

1 carat expressed in every weight unit
UnitValueExact factor
ounces0.00705479239 oz× 0.00705479238992
pounds0.0004409245244 lb× 0.00044092452437
stone0.00003149460888 st× 0.0000314946088836
US tons0.0000002204622622 ton× 0.000000220462262185
micrograms200,000 mcg× 200,000
milligrams200 mg× 200
centigrams20 cg× 20
grams0.2 g× 0.2
kilograms0.0002 kg× 0.0002
slugs0.00001370435317 slug× 0.0000137043531714
tonnes0.0000002 t× 0.0000002
carats (as entered)1 ct—
troy ounces0.006430149314 ozt× 0.00643014931373
grains3.086471671 gr× 3.08647167059
long tons0.0000001968413055 LT× 0.000000196841305522

Factors are entered by hand from NIST Handbook 44 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert carats to centigrams? The converter and the working

  1. 1.Take the measurement in carats.
  2. 2.Multiply by 20 — that is how many centigrams fit in one carat.
  3. 3.To go back the other way, divide by 20, or multiply by 0.05.

Worked example: 25 carats to centigrams

Formula
ct × 20 = cg
Arithmetic
25 × 20 = 500 cg
Answer
25 ct = 500 cg

The factor is exact, so this figure is exact too — only the display is rounded.

Carats to centigrams conversion table

Carats to centigrams conversion table
CaratsCentigrams
1 ct20 cg
2 ct40 cg
3 ct60 cg
4 ct80 cg
5 ct100 cg
6 ct120 cg
7 ct140 cg
8 ct160 cg
9 ct180 cg
10 ct200 cg
12 ct240 cg
15 ct300 cg
20 ct400 cg
25 ct500 cg
50 ct1,000 cg
100 ct2,000 cg
200 ct4,000 cg
300 ct6,000 cg
500 ct10,000 cg
1000 ct20,000 cg
2000 ct40,000 cg
5000 ct100,000 cg
10000 ct200,000 cg

What is a carat?

Exactly 200 milligrams, fixed by international agreement in 1907 after centuries of local carats. It weighs a gemstone; the karat that grades gold is a different word for a different thing — purity in twenty-fourths.

What is a centigram?

A hundredth of a gram, or ten milligrams. It survives mainly in pharmacology and in school exercises about metric prefixes.

How many centigrams are in a carat?

One carat is 20 centigrams, exactly. Going the other way, one centigram is 0.05 carats. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every weight unit here

The whole group — 15 units with their symbols and the size of each one in kilograms — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a carat.

Source: NIST Handbook 44 — mass and weight

Cite this page

APA
Rule Calculator. (2026). Convert Carats to centigrams. Rule Calculator. https://rulecalculators.com/convert/carat-to-centigram
MLA
"Convert Carats to centigrams." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/carat-to-centigram.
Chicago
Rule Calculator. "Convert Carats to centigrams." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/carat-to-centigram.

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Questions people actually ask

How many centigrams are in a carat?
20. A hundredth of a gram, or ten milligrams. It survives mainly in pharmacology and in school exercises about metric prefixes.
How do I convert centigrams back to carats?
Divide by 20, or multiply by 0.05 — they are the same operation.

Other weight conversions

Centigrams to carats — the same conversion the other way.

Calculators that work in weight