⚖️ ct to kg — Carat to Kilogram Converter

Convert weight and mass units — kilograms, pounds, grams, ounces, tons, carats and more.

1 unit =
From
To
Formula 1 ct = 0.0002 kg
Quick Answer — Formula1 ct = 0.0002 kgMultiply carats by 0.0002 to get kilograms.Reverse: 1 kg = 5000 ct
UnitNameValue
0.001 ct2e-07 kg
0.01 ct2e-06 kg
0.1 ct2e-05 kg
1 ct0.0002 kg
5 ct0.001 kg
10 ct0.002 kg
50 ct0.01 kg
100 ct0.02 kg
1000 ct0.2 kg

About Carat to Kilogram Conversion

The Milligram (mg) and the Gram (g) are both units of weight & mass. Converting between them is straightforward using the formula above.

Formula: 1 ct = 0.0002 kg

This converter uses internationally recognized conversion factors. All calculations are performed client-side in your browser — no data is sent to any server.

Worked Examples: Carat to Kilogram

A 1-carat diamond solitaire
1 ct = 0.0002 kg
The classic engagement ring stone is a 1-carat diamond = 0.2 g. Jewellers worldwide quote gemstone weight in carats and fractions of carats.
A large gemstone
5 ct = 0.001 kg
A 5-carat ruby is considered a fine specimen — it weighs just 1 gram, showing how small even prestigious gemstones truly are.
A tola of gold bar
1 ct = 0.0002 kg
A 1-tola gold bar (≈11.66 g) is the most common retail gold investment unit across India, Pakistan, and UAE.
A gem-quality sapphire
3 ct = 0.0006 kg
A 3-carat blue sapphire weighs 0.6 g. The per-carat price of fine sapphires can exceed $10,000, so precise weight measurement is critical.

Carat to Kilogram Reference Table

Carat (ct)Kilogram (kg)Real-world context
1 ct0.0002 kgsolitaire diamond
100 ct0.02 kg
1000 ct0.2 kg
10000 ct2 kg
100000 ct20 kg

Mental Math Tricks: Carat to Kilogram

Divide by 5000
Since the factor is small (0.0002), it's easier to divide: kg value ÷ 5000 = ct value.
Use scientific notation
1 ct = 2.00e-04 kg. Count decimal places carefully.
Think in larger units first
Convert to a more familiar unit first, then to kg.

When to Convert Carat to Kilogram

💎 Jewellery Design Jewellers specify gemstone weights in carats and metal weights in grams or tola. Converting ct to kg is a core skill in jewellery making.
🏆 Gemstone Grading The 4Cs of diamond grading include carat weight. Converting between ct and kg helps compare stones across different grading systems.
💰 Gold Trading Gold prices are quoted per gram, per tola, and per troy ounce depending on the market. Carat to Kilogram conversion is essential for traders and investors.
⚖️ Hallmarking Precious metal hallmarking authorities certify weights in specific units. Convert between ct and kg for compliance and documentation.
🎯 Archery & Ballistics Arrow and bullet weights are specified in grains. Converting to grams or vice versa is routine for archers and competitive shooters.
🏛️ Antique Appraisal Historical weights for silver and gold artefacts may be recorded in ct. Converting to modern kg helps calculate material value accurately.

Frequently Asked Questions — Carat to Kilogram

1 carat (ct) equals exactly 0.0002 kilograms (kg). Use the formula: ct × 0.0002 = kg.

To convert carats to kilograms, multiply your value in carats by 0.0002. For example, 5 ct × 0.0002 = 0.001 kg.

100 carats = 0.02 kilograms. Calculation: 100 × 0.0002 = 0.02.

To convert kilograms back to carats, divide by 0.0002 (or multiply by 5000). Example: 10 kg ÷ 0.0002 = 50000 ct.

Yes. This converter uses the internationally recognised exact conversion factor: 1 ct = 0.0002 kg. All calculations are performed in your browser with no rounding until display.

10 carats = 0.002 kilograms. Simply multiply by 0.0002.

Converting carats to kilograms is commonly needed for jewellery valuation, gemstone trading, precious metal buying and selling, and hallmarking compliance where one system uses ct and another uses kg.

Understanding Carat and Kilogram

Carat (ct)

The metric carat (ct) is the unit of mass used worldwide for gemstones and pearls, equal to exactly 200 milligrams (0.2 g). It is distinct from "karat" (K), the measure of gold purity (24K = 100% gold). A 1-carat diamond weighs exactly 0.2 g; the famous 45.52-carat Hope Diamond weighs approximately 9.1 g.

Kilogram (kg)

The kilogram (kg) is the SI base unit of mass — one of seven fundamental units in the International System. Equal to exactly 1,000 grams, it is the foundation of weight measurement in science, medicine, engineering, and commerce worldwide. Uniquely among SI base units, the kilogram is named with a metric prefix ("kilo-" = 1,000).

History of the Carat

The word "carat" derives from Greek keration (κεράτιον), meaning carob pod. Carob seeds were believed to have remarkably uniform weight and were used as counterweights for balancing precious stones. The carat value varied across countries (0.187–0.216 g) until the Fourth General Conference on Weights and Measures standardised the metric carat at exactly 200 mg in 1907. Most countries adopted the metric carat between 1914 and 1930.

Interesting fact: The largest gem-quality diamond ever found, the Cullinan Diamond (1905), weighed 3,106.75 carats (621.35 g) before being cut into 9 major and 96 minor stones, two of which are in the British Crown Jewels.

History of the Kilogram

Defined in 1795 by the French Revolutionary government as the mass of one cubic decimetre of distilled water at 4 °C. A platinum prototype (the Kilogramme des Archives) was created in 1799. From 1889 until 2019, the world's mass standard was the International Prototype Kilogram — a platinum-iridium cylinder stored in Sèvres, France. In 2019, the kilogram was redefined in terms of Planck's constant (h = 6.626 070 15 × 10⁻³⁴ J·s), eliminating the need for a physical artifact.

Interesting fact: The IPK and its official copies drifted apart by up to 50 micrograms over 130 years, motivating the 2019 redefinition. The kilogram is the only SI unit whose name starts with a prefix.