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Convert Carats to Kilograms

1 carat is 0.0002 kg. One carat is exactly 0.0002 kilograms.

One carat is 2.0000 × 10^-4 kilograms. To convert carats to kilograms, multiply by 2.0000 × 10^-4; to go the other way, divide by 2.0000 × 10^-4 or multiply by 5000. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and 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

Kilograms
0.0002 kg
Carats × 2.0000 × 10^-4
1 * 0.00020 kg

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 kilograms? The converter and the working

  1. 1.Take the measurement in carats.
  2. 2.Multiply by 2.0000 × 10^-4 — that is how many kilograms fit in one carat.
  3. 3.To go back the other way, divide by 2.0000 × 10^-4, or multiply by 5000.

Worked example: 25 carats to kilograms

Formula
ct × 2.0000 × 10^-4 = kg
Arithmetic
25 × 2.0000 × 10^-4 = 0.01 kg
Answer
25 ct = 0.01 kg

The factor is rounded for display; the figure above is computed from the full value.

Carats to kilograms conversion table

Carats to kilograms conversion table
CaratsKilograms
1 ct0.0002 kg
2 ct0.0004 kg
3 ct0.0006 kg
4 ct0.0008 kg
5 ct0.001 kg
6 ct0.0012 kg
7 ct0.0014 kg
8 ct0.0016 kg
9 ct0.0018 kg
10 ct0.002 kg
12 ct0.0024 kg
15 ct0.003 kg
20 ct0.004 kg
25 ct0.01 kg
50 ct0.01 kg
100 ct0.02 kg
200 ct0.04 kg
300 ct0.06 kg
500 ct0.1 kg
1000 ct0.2 kg
2000 ct0.4 kg
5000 ct1 kg
10000 ct2 kg

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 kilogram?

The SI base unit of mass, defined since 2019 by fixing the Planck constant rather than by a metal cylinder in Paris.

How many kilograms are in a carat?

One carat is 2.0000 × 10^-4 kilograms. Going the other way, one kilogram is 5000 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 kilograms. Rule Calculator. https://rulecalculators.com/convert/carat-to-kilogram
MLA
"Convert Carats to kilograms." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/carat-to-kilogram.
Chicago
Rule Calculator. "Convert Carats to kilograms." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/carat-to-kilogram.

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Questions people actually ask

How many kilograms are in a carat?
2.0000 × 10^-4. The SI base unit of mass, defined since 2019 by fixing the Planck constant rather than by a metal cylinder in Paris.
How do I convert kilograms back to carats?
Divide by 2.0000 × 10^-4, or multiply by 5000 — they are the same operation.

Other weight conversions

Kilograms to carats — the same conversion the other way.

Calculators that work in weight