Convert weight and mass units — kilograms, pounds, grams, ounces, tons, carats and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 ct | 0.0002 g | |
| 0.01 ct | 0.002 g | |
| 0.1 ct | 0.02 g | |
| 1 ct | 0.2 g | |
| 5 ct | 1 g | |
| 10 ct | 2 g | |
| 50 ct | 10 g | |
| 100 ct | 20 g | |
| 1000 ct | 200 g |
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 = 0.2 g
This converter uses internationally recognized conversion factors. All calculations are performed client-side in your browser — no data is sent to any server.
| Carat (ct) | Gram (g) | Real-world context |
|---|---|---|
| 1 ct | 0.2 g | solitaire diamond |
| 10 ct | 2 g | collector gem |
| 100 ct | 20 g | |
| 500 ct | 100 g | |
| 1000 ct | 200 g |
1 carat (ct) equals exactly 0.2 grams (g). Use the formula: ct × 0.2 = g.
To convert carats to grams, multiply your value in carats by 0.2. For example, 5 ct × 0.2 = 1 g.
100 carats = 20 grams. Calculation: 100 × 0.2 = 20.
To convert grams back to carats, divide by 0.2 (or multiply by 5). Example: 10 g ÷ 0.2 = 50 ct.
Yes. This converter uses the internationally recognised exact conversion factor: 1 ct = 0.2 g. All calculations are performed in your browser with no rounding until display.
10 carats = 2 grams. Simply multiply by 0.2.
Converting carats to grams is commonly needed for jewellery valuation, gemstone trading, precious metal buying and selling, and hallmarking compliance where one system uses ct and another uses g.
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.
The gram (g) is a unit of mass in the metric system equal to one-thousandth of a kilogram (0.001 kg). While the kilogram is the SI base unit, the gram is the practical everyday unit for small masses in cooking, pharmacy, chemistry, and nutrition labelling. The word derives from Late Latin gramma (small weight), itself from Greek.
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.
Defined in 1795 by the French Academy of Sciences as the mass of one cubic centimetre of pure water at 4 °C — this made 1 mL of water weigh almost exactly 1 gram. The gram was the practical base of early metric calculations before the kilogram took over as SI base unit in 1875. The relationship 1 mL water ≈ 1 g is still a useful approximation in cooking and chemistry.
Interesting fact: A standard large paperclip weighs about 1 gram. The gram forms the basis for milligram (mg), microgram (μg), and tonne (10⁶ g) through SI prefixes.