Convert Carat to Gram
1 carat = 0.2 gram (g). For example, 10 carat = 2 gram and 100 carat = 20 gram. Type any value below to convert carat to gram both ways — it runs entirely in your browser.
Quick answer: Carat to Gram
1 Carat = 0.2 Gram (ct → g). To convert carat to gram, multiply by 0.2. To convert gram to carat, multiply by 5. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common carat-to-gram questions.
How to convert Carat to Gram
To convert carat to gram, multiply the number of carat by the conversion factor 0.2, because 1 ct = 0.2 g. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 g = 5 ct, so you divide by 0.2 (or multiply by 5) to turn gram back into carat.
g = ct × 0.2 ·
ct = g × 5
- Write down the value you want to convert, in carat.
- Multiply it by 0.2.
- The result is the same area/length/quantity expressed in gram.
Carat to Gram — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 carat is 1 gram because 5 ct × 0.2 = 1 g.
| Carat | Calculation | Gram |
|---|---|---|
| 1 ct | 1 ct × 0.2 = 0.2 g | 0.2 g |
| 2 ct | 2 ct × 0.2 = 0.4 g | 0.4 g |
| 3 ct | 3 ct × 0.2 = 0.6 g | 0.6 g |
| 5 ct | 5 ct × 0.2 = 1 g | 1 g |
| 7 ct | 7 ct × 0.2 = 1.4 g | 1.4 g |
| 10 ct | 10 ct × 0.2 = 2 g | 2 g |
| 12 ct | 12 ct × 0.2 = 2.4 g | 2.4 g |
| 15 ct | 15 ct × 0.2 = 3 g | 3 g |
| 20 ct | 20 ct × 0.2 = 4 g | 4 g |
| 25 ct | 25 ct × 0.2 = 5 g | 5 g |
| 50 ct | 50 ct × 0.2 = 10 g | 10 g |
| 100 ct | 100 ct × 0.2 = 20 g | 20 g |
Common Carat to Gram conversions
These are the carat-to-gram values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 carat = 0.2 gram
- 2 carat = 0.4 gram
- 2.5 carat = 0.5 gram
- 3 carat = 0.6 gram
- 4 carat = 0.8 gram
- 5 carat = 1 gram
- 6 carat = 1.2 gram
- 7 carat = 1.4 gram
- 8 carat = 1.6 gram
- 9 carat = 1.8 gram
- 10 carat = 2 gram
- 12 carat = 2.4 gram
- 15 carat = 3 gram
- 20 carat = 4 gram
- 25 carat = 5 gram
- 30 carat = 6 gram
- 50 carat = 10 gram
- 75 carat = 15 gram
- 100 carat = 20 gram
- 200 carat = 40 gram
- 500 carat = 100 gram
- 1000 carat = 200 gram
Carat to Gram conversion chart (both directions)
The chart below converts carat to gram and gram to carat side by side, so it works whichever way you need. 1 carat = 0.2 gram, and 1 gram = 5 carat.
| Carat → Gram | Gram → Carat |
|---|---|
| 0.25 ct = 0.05 g | 0.25 g = 1.25 ct |
| 0.5 ct = 0.1 g | 0.5 g = 2.5 ct |
| 1 ct = 0.2 g | 1 g = 5 ct |
| 2 ct = 0.4 g | 2 g = 10 ct |
| 3 ct = 0.6 g | 3 g = 15 ct |
| 4 ct = 0.8 g | 4 g = 20 ct |
| 5 ct = 1 g | 5 g = 25 ct |
| 6 ct = 1.2 g | 6 g = 30 ct |
| 7 ct = 1.4 g | 7 g = 35 ct |
| 8 ct = 1.6 g | 8 g = 40 ct |
| 9 ct = 1.8 g | 9 g = 45 ct |
| 10 ct = 2 g | 10 g = 50 ct |
| 12 ct = 2.4 g | 12 g = 60 ct |
| 15 ct = 3 g | 15 g = 75 ct |
| 20 ct = 4 g | 20 g = 100 ct |
| 25 ct = 5 g | 25 g = 125 ct |
| 30 ct = 6 g | 30 g = 150 ct |
| 40 ct = 8 g | 40 g = 200 ct |
| 50 ct = 10 g | 50 g = 250 ct |
| 75 ct = 15 g | 75 g = 375 ct |
| 100 ct = 20 g | 100 g = 500 ct |
| 150 ct = 30 g | 150 g = 750 ct |
| 200 ct = 40 g | 200 g = 1,000 ct |
| 250 ct = 50 g | 250 g = 1,250 ct |
| 500 ct = 100 g | 500 g = 2,500 ct |
| 1000 ct = 200 g | 1000 g = 5,000 ct |
Carat vs Gram: which is bigger?
A gram is the larger unit: one gram equals 5 carats. Put another way, you need 5 carats to make a single gram.
What is a Carat? History, origin and usage
The carat takes its name from the carob seed — keration in Greek — which gem traders used as a counterweight because the seeds were believed to be unusually uniform. They were not, in fact, especially uniform, and the carat varied from city to city until the 4th General Conference on Weights and Measures adopted the metric carat of exactly 200 milligrams in 1907.
The carat is the weight unit of the gemstone trade. Diamond, ruby, sapphire and emerald weights are quoted in carats, and because price rises steeply with size, a stone of twice the carat weight can cost far more than twice as much.
Carat weight and karat purity are different things that sound identical: a 2-carat diamond is a statement about mass, while 22-karat gold is a statement about how much of an alloy is gold, out of 24 parts. Jewellers also split the carat into 100 "points", so a 0.25-carat stone is called a 25-pointer.
What is a Gram? History, origin and usage
The gram was defined in 1795 as the mass of one cubic centimetre of water at the melting point of ice. It was meant to be the everyday unit, with the kilogram as a bulk multiple — but the kilogram turned out to be the more practical size for a physical standard, so the two swapped roles and the gram became the derived one.
Grams are the normal unit for food, recipes, spices, postage, jewellery and laboratory work — anything too small to weigh comfortably in kilograms. Nutrition labels almost everywhere give protein, fat and sugar in grams.
The gram was the base unit of the old CGS (centimetre-gram-second) system used in physics before SI took over. A gram is roughly the mass of a paperclip, or of one millilitre of water.
Convert 1 Carat to other units
It can help to see a carat next to the other units it is commonly compared with. One carat (ct) is equal to:
| 1 Carat equals | Unit |
|---|---|
| 0.0002 kg | Kilogram |
| 0.2 g | Gram |
| 200 mg | Milligram |
| 200,000 µg | Microgram |
| 0.0000002 t | Tonne |
| 0.000002 q | Quintal |
| 0.0004409245 lb | Pound |
| 0.007054792 oz | Ounce |
| 0.00003149461 st | Stone |
| 0.0000002204623 ton (US) | Short ton |
| 0.0000001968413 ton (UK) | Long ton |
| 0.006430149 oz t | Troy ounce |
| 3.086472 gr | Grain |
Convert 1 Gram to other units
One gram (g) is equal to:
| 1 Gram equals | Unit |
|---|---|
| 0.001 kg | Kilogram |
| 1,000 mg | Milligram |
| 1,000,000 µg | Microgram |
| 0.000001 t | Tonne |
| 0.00001 q | Quintal |
| 0.002204623 lb | Pound |
| 0.03527396 oz | Ounce |
| 0.000157473 st | Stone |
| 0.000001102311 ton (US) | Short ton |
| 0.0000009842065 ton (UK) | Long ton |
| 0.03215075 oz t | Troy ounce |
| 15.43236 gr | Grain |
| 5 ct | Carat |
Tips for converting Carat to Gram
- To go from carat to gram, multiply by 0.2; to go back, divide by 0.2 (or multiply by 5).
- For a quick mental estimate, remember that 1 carat ≈ 0.2 gram, so 10 carat ≈ 2 gram.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this Carat to Gram converter
Type a number into the Carat field and the equivalent in Gram appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Gram field to convert the other way (gram to carat). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 ct = 0.2 g), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for carat-to-gram conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
- NIST — Definitions of the SI base units — the US National Institute of Standards and Technology reference for the SI base units, used here as an independent cross-check on the base-unit definition.
Weight factors here are exact, anchored to the kilogram: the international pound is exactly 0.45359237 kg, a stone is 14 pounds, a short ton is 2,000 pounds and a long ton is 2,240, a grain is 1/7000 of a pound and a metric carat is exactly 200 mg. So the live tool and every number on this page always agree.
Frequently asked questions
- How many gram are in 1 carat?
- 1 carat = 0.2 gram (g). To convert any number of carat to gram, multiply by 0.2.
- How do I convert carat to gram?
- Multiply the number of carat by 0.2. For example, 10 carat = 10 × 0.2 = 2 gram, and 25 carat = 5 gram.
- How many carat are in 1 gram?
- 1 gram = 5 carat. So to convert gram back to carat, multiply by 5.
- What is the formula to convert carat to gram?
- gram = carat × 0.2. The reverse formula is carat = gram × 5.
- How much is 100 carat in gram?
- 100 carat = 20 gram. (And 1000 carat = 200 gram.)
- Which is bigger, a carat or a gram?
- A gram is larger: 1 gram = 5 carat.
- Is this carat to gram converter accurate?
- Yes — every value is computed from the exact 0.2 g per ct factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert gram to carat too?
- Yes. The converter works both ways — enter a value in either field. 1 gram = 5 carat.