How many carats are in one kilogram?

There are exactly 5,000 metric carats in one kilogram. This follows from the definition of the metric carat: 1 ct = 0.2 g, so 1 kg (= 1,000 g) ÷ 0.2 g/ct = 5,000 ct.

What is a metric carat?

The metric carat (symbol ct) is a unit of mass equal to exactly 0.2 grams (200 milligrams). It has been the international standard for weighing diamonds and gemstones since 1907 and is used by the jewelry trade worldwide.

Is the carat used for gold the same as the gemstone carat?

No. The gemstone carat (ct) is a unit of mass (0.2 g). The gold karat (k or kt) is a measure of purity — 24-karat gold is pure gold. They share a similar name but measure entirely different things.

Why do gemologists use carats instead of grams?

Carats give conveniently sized numbers for gemstones. A 1-carat diamond weighs only 0.2 g — expressing it as 0.2 g is awkward in trading. Using carats keeps numbers in a practical range (e.g., 0.50 ct, 1.25 ct) and aligns with international grading standards.

Can I convert grams to carats with this tool?

This tool converts between kilograms and carats. Because 1 kg = 1,000 g = 5,000 ct, you can also derive grams-to-carats: multiply your gram value by 5 (since 1 g = 5 ct).

Kilograms to Carats Converter

Enter a mass in kilograms and instantly get the equivalent weight in metric carats (1 kg = 5,000 ct).

Mass Converter

Kilograms (kg)

Carats (ct)

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Grams (g)

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1 kg = 5,000 ct • 1 ct = 0.2 g = 0.0002 kg

Quick Reference Table

Kilograms (kg)	Carats (ct)	Grams (g)

Carats (ct)	Kilograms (kg)	Grams (g)

1 metric carat = 0.2 g (exact) • Standard since 1907 • Used worldwide in gemology

Summary

This tool converts mass values in kilograms (kg) to metric carats (ct). One kilogram equals exactly 5,000 metric carats, because one carat is defined as 0.2 grams (200 milligrams). The metric carat is the international standard unit for weighing diamonds, gemstones, and precious materials. The reference table below covers the most common kilogram values used in gemology and precious-metal trading.

How it works

Enter a mass value in kilograms in the input field.
The converter instantly displays the equivalent weight in metric carats.
The gram equivalent is also shown for cross-reference.
Click the swap button to reverse the direction and convert carats to kilograms.
Use the quick-reference table for common conversions at a glance.

Use cases

Convert bulk gemstone inventory weights from kilograms to carats.
Calculate the carat weight of rough diamond or ruby parcels.
Check precious-metal trading quantities against industry carat standards.
Convert laboratory specimen masses for gemological certification.
Verify gemstone shipment weights when switching between unit systems.
Estimate retail value of a parcel by knowing total carat weight.

Frequently Asked Questions

Last updated: 2026-10-05 · Reviewed by Nham Vu