Converting Carats to Grams (ct to g) is essential for jewelers, gemologists, and anyone looking to buy a diamond or engagement ring. It is important not to confuse “Carat” (weight of a stone) with “Karat” (purity of gold). The metric carat is a standardized unit of mass equal to exactly 0.2 grams (or 200 milligrams). This means a 1-carat diamond weighs roughly the same as a paperclip.
Master Weight Converter
The Formula
Multiply the number of Carats by 0.2:
Carats × 0.2 = Grams
Example
If you have a large diamond that weighs 5.00 Carats:
5.00 × 0.2 = 1.00 Gram
Jewelry Weight Made Simple
The easiest way to remember this conversion is that 5 carats = 1 gram. If you are holding a 5-carat diamond, it weighs exactly the same as a standard 1-gram paperclip!
Frequently Asked Questions
One carat is exactly one-fifth of a gram (0.2g). This measurement was standardized globally in 1907. Before that, people used carob seeds to weigh gems, which is actually where the word “carat” comes from!
If you have the carat weight, just divide by 5.
• 1 Carat = 0.2g
• 2.5 Carats = 0.5g (Half a gram)
• 5 Carats = 1g
This is the most common mistake in the jewelry world! Remember: **C**arat is for **C**ones (the shape of a diamond) and measures weight. **K**arat is for **K**arat-gold and measures how much pure gold is mixed with other metals. Our converter here is for weight (Carats).
To visualize 0.2 grams, imagine a standard $8 \times 11$ sheet of printer paper. If you cut a tiny square out of that paper about the size of a fingernail, that would weigh roughly 1 carat. It is amazing that something so light can be so valuable!