1 Carat in Grams: Conversion Chart & Easy Calculation Guide

When buying gemstones, diamonds, or working with jewellery measurements, you will often hear the term carat. But what does a carat really mean in terms of weight, and how does 1 carat in grams translate in real-world measurements?

This guide explains 1 carat in grams, provides a simple conversion chart, walks you through easy calculations, and clears up common confusion with practical examples. By the end, you’ll be able to convert carats to grams quickly and confidently.

What Is a Carat and How Does 1 Carat in Grams Work?

A carat (ct) is a unit of weight used specifically for gemstones and diamonds. It does not measure size, shape, or value but only weight.

Today, the carat is standardized worldwide, meaning the same measurement is used everywhere in the jewelry industry.

Standard Definition:

1 carat = 0.2 grams

This international standard was officially adopted in 1907, ensuring consistency across countries and markets.

1 Carat in Grams (Simple Answer)

1 carat = 0.2 grams

That’s it. Every gemstone weighed at 1 carat will always weigh 0.2 grams, regardless of its shape, color, or type.

Why Is Carat Weight Important?

Carat weight matters because it directly affects:

• Gemstone value
• Jewelry pricing
• Accuracy in trading
• Fair buying and selling

Even small differences in carat weight can significantly impact price, especially for diamonds.

Carat to Gram Conversion Formula

Converting carats to grams is very easy once you know the formula.

Formula:

Grams = Carats × 0.2

Example:

• 1 carat × 0.2 = 0.2 grams
• 2 carats × 0.2 = 0.4 grams

Grams to Carats Formula (Reverse Conversion)

If you want to convert grams back into carats:

Formula:

Carats = Grams ÷ 0.2

Example:

• 1 gram ÷ 0.2 = 5 carats
• 0.5 grams ÷ 0.2 = 2.5 carats

1 Carat in Grams Conversion Chart (Carat to Gram Table)

Here’s a quick-reference chart for common gemstone weights:

Carats (ct)	Grams (g)
0.25 ct	0.05 g
0.50 ct	0.10 g
0.75 ct	0.15 g
1.00 ct	0.20 g
1.50 ct	0.30 g
2.00 ct	0.40 g
3.00 ct	0.60 g
4.00 ct	0.80 g
5.00 ct	1.00 g
10.00 ct	2.00 g

Tip: Every 5 carats equal exactly 1 gram.

Easy Mental Math Trick to Calculate 1 Carat in Grams

If you don’t want to use formulas, try this:

• Divide carats by 5 , you get grams
• Multiply grams by 5 , you get carats

Example:

• 2.5 carats ÷ 5 = 0.5 grams
• 0.6 grams × 5 = 3 carats

This trick works every time.

Carat vs Gram: What’s the Difference?

Feature	Carat	Gram
Used for	Gemstones	General weight
Industry	Jewelry	Science, cooking
Metric	Yes	Yes
Standardized	Yes	Yes
Conversion	1 ct = 0.2 g	1 g = 5 ct

While grams are used in everyday life, carats are preferred in jewelry because they allow for more precise measurement of small, valuable stones.

Does Carat Measure Size?

No. Carat measures weight, not size.

Two gemstones can have:

• The same carat weight
• But different sizes

Why? Because density varies between gemstones.

Example:

• A 1 carat diamond may look smaller than a 1 carat emerald
• This is due to differences in density and cut

Common Mistakes to Avoid

1. Confusing carat with karat
   • Carat = gemstone weight
   • Karat = gold purity (e.g., 24K gold)
2. Assuming higher carat means larger size
   • Shape and density matter
3. Using outdated conversions
   • Always use the modern standard: 1 ct = 0.2 g

Why Jewelers Use Carats Instead of Grams

• Greater precision for small weights
• International standardization
• Clear pricing tiers
• Industry-wide consistency

Using grams alone would make small gemstones harder to price accurately.

Frequently Asked Questions (FAQs)