Last updated:

# Diamond Carat Calculator

How to calculate the carats of a diamond?Girdle thickness, weight correction, and adjustment factorOther similar toolsFAQs

Diamonds symbolize luxury, elegance, and timeless beauty, but when it comes to buying one, it's not just about the looks: it's also about its weight and size, and that's where the diamond carat calculator gets in.

Carat weight is one of the most important factors determining a diamond's value. With the help of this diamond carat calculator, you can quickly calculate the total carat weight of a diamond based on its dimensions and make an informed buying or selling decision.

So, let's dive into the world of diamonds and explore how to calculate diamond carats.

## How to calculate the carats of a diamond?

Our tool uses the following formulas to calculate the total carat weight of the piece of diamond:

• Asscher = Length × Width × Depth × 0.0080 × (1 + GT) × (1 + WC);
• Baguette = Length × Width × Depth × 0.00915 × (1 + GT) × (1 + WC);
• Cushion = Length × Width × Depth × 0.00815 × (1 + GT) × (1 + WC);
• Emerald = Length × Width × Depth × AF × (1 + GT) × (1 + WC);
• Heart = Length × Width × Depth × 0.0059 × (1 + GT) × (1 + WC);
• Oval = Length × Width × Depth × 0.0062 × (1 + GT) × (1 + WC);
• Princess = Length × Width × Depth × 0.0083 × (1 + GT) × (1 + WC);
• Round = Diameter² × Depth × 0.0061 × (1 + GT);
• Trillion = Length × Width × Depth × 0.0057 × (1 + GT) × (1 + WC);
• Marquise: Length × Width × Depth × AF × (1 + GT) × (1 + WC);
• Pear: Length × Width × Depth × AF × (1 + GT) × (1 + WC); and
• Radiant: Length × Width × Depth × AF × (1 + GT) × (1 + WC)

💡 where:

• GT: Girdle thickness factor;
• WC: Weight correction factor; and

💡 To correctly calculate the total carat weight with the previous formulas, the length, width, depth, and diameter must be input in millimeters. For round diamonds, the depth is around 60% of the diameter.

## Girdle thickness, weight correction, and adjustment factor

To know how to calculate the carats of a diamond more accurately, you must consider the following factors:

• GT is the ratio of the girdle thickness to the diamond diameter, usually expressed as a percentage.
• Because of the difficulty of measuring that tiny thickness, most of the time, GT is estimated visually;
• It usually lies between 1% (0.01) and 3% (0.03) for round diamonds.
• The weight correction factor accounts for estimation errors caused by non-regular or non-standard shapes.
• The adjustment factor depends on the length-to-width ratio. This diamond carat calculator finds it for you automatically.

## Other similar tools

Looking for more about diamonds? Check out Omni's collection:

FAQs

### What is the weight in carat of an 8×6 mm diamond?

The weight in carats of an 8×6 mm oval diamond will be 1.071-carat, assuming a 3.6 mm depth. The exact answer will depend on the diamond depth, girdle thickness, and geometric irregularities.

### How big is a 2-carat diamond?

A 2-carat round diamond has a diameter or width of 8 mm, approximately, but the exact weight will depend on the diamond diameter, depth, and girdle thickness. Find it out with our carat calculator!