Diamond Weight Calculator

Created By : Vinay Kumar Prajapati

Reviewed By : Rajashekhar Valipishetty

Last Updated : May 07, 2025

Just enter the dimensions of the diamond in the input field of the Free Diamond Weight Calculator & tap on the Calculate button to attain the output. It completes your mathematical computations quickly and shows the result in a blink of an eye.

Diamond Weight Calculator: Trying to find out the estimated carat weight of your diamond? For representing the statistics of the diamond this Diamond Carat Weight Calculator is a very useful tool for anyone. For instance, if you desire to determine a set of observations for the diamond then you can smoothly take the assistance from our online tool which is easy to use & faster.

What are the Different Shapes of Diamond? | How to Calculate Diamond Weight Easily?

Nowadays, diamonds are sold in different shapes & sizes. The most popular type of diamond is the round-shaped one. Almost ¾th of sales of diamonds all over the world are round diamonds. Other shaped diamonds are also gaining popularity now, because in most cases less costly compared to round shaped diamonds.

What is a Carat?

It is a unit used for measuring gems. The carat unit was not uniformed a few decades ago. So, to avoid conflict & standardize the unit, a universal weight for carat is determined. So, a carat is equal to 0.007055 oz or 200 mg.

i.e., 1 carat = 200 mg or 0.007055 oz

Diamond Weight Calculator Formula to Calculate Various Diamond Shapes

Following are the weight estimation formulae for different shapes of diamonds:

Round Brilliant shape:

Approximate Carat Weight = (Diameter) 2 × Depth × 0.0061 × GTF

Oval shape:

Approximate Carat Weight = Length × Width × Depth × 0.0062 × GTF × WCF

Princess Cut shape:

Approximate Carat Weight = Length × Width × Depth × 0.0083 × GTF × WCF

Asscher Cut shape:

Approximate Carat Weight = Length × Width × Depth × 0.0080 × GTF × WCF

Cushion Cut shape:

Approximate Carat Weight = Length × Width × Depth × 0.00815 × GTF × WCF

Heart shape:

Approximate Carat Weight = Length × Width × Depth × 0.0059 × GTF × WCF

Baguette shape:

Approximate Carat Weight = Length × Width × Depth × 0.00915 × GTF × WCF

Trillion Cut shape:

Approximate Carat Weight = Length × Width × Depth × 0.0057 × GTF × WCF

Emerald Cut shape:

Approximate Carat Weight = Length × Width × Depth × Adjustment Factor × GTF × WCF

Length to Width Ratio

Adjustment Factor

1.00: 1.00

0.0080

1.50: 1.00

0.0092

2.00: 1.00

0.0100

2.50: 1.00

0.0106

 

Radiant Cut shape:

Approximate Carat Weight = Length × Width × Depth × Adjustment Factor × GTF × WCF

Marquise Cut Shape:

Approximate Carat Weight = Length × Width × Depth × Adjustment Factor × GTF × WCF

Pear Shape Formula:

Approximate Carat Weight = Length × Width × Depth × Adjustment Factor × GTF × WCF

Here, GTF = Girdle Thickness Factor, WCF = Weight Correction Factor.

How Do You Calculate Diamond Weight in Carats Manually?

The manual process that you need to follow while calculating the diamond of your required shape in carat is listed below. Check the steps properly and get the estimated weight of your diamond in no time:

  1. Check the diamond shape you want to buy.
  2. Give the dimensions of the diamond (the diameter or length, width & depth).
  3. Check the girdle thickness & if applicable, use the weight correction factor.
  4. Use the formula to calculate weight in carats.
  5. Finally, you get the desired weight of the diamond shape accurately.

Finding the mathematical problems tough? You can find the best calculator tools on our site onlinecalculator.guide which is free to use and easy to understand while performing the calculations.

Solved Example on Diamond Carat Weight Calculator

Example:

Calculate weight in carat for a round-shaped diamond having a diameter of 12mm & depth of 8mm. Also, diamond is slightly thick, that is 2% girdle thickness.

Solution:

Here, the formula to calculate the weight of a diamond is

Diamond Carat Weight (D) = Length x Width x Depth x Coefficient

Approximate Carat Weight = (Diameter) 2 × Depth × 0.0061 × GTF

Here, diameter = 12mm, depth = 8mm & girdle thickness factor = 2%

So, using the formula,

Approximate Carat Weight = 7.168 carats

Round Shape Sizing Diamond Weight Chart

The following table is the diamond weight chart for estimating a round brilliant sizing. Want to know more do reach us on our main page.

MM Size

Carat Weight

MM Size

Carat Weight

0.8

0.0025

7

1.28

1

0.005

7.25

1.49

1.12

0.0075

7.5

1.67

1.15

0.0067

7.75

1.75

1.25

0.01

8

2.04

1.3

0.01

8.25

2.11

1.5

0.015

8.5

2.43

1.75

0.02

8.75

2.55

1.8

0.025

9

2.75

2

0.03

9.25

3.05

2.25

0.04

9.5

3.35

2.5

0.06

9.75

3.61

2.75

0.08

10

3.87

3

0.11

10.25

4.16

3.25

0.14

10.5

4.41

3.5

0.17

10.75

4.57

3.75

0.21

11

4.91

4

0.25

11.25

5.49

4.25

0.28

11.5

5.85

4.5

0.36

12

6.84

4.75

0.44

12.25

7.26

5

0.46

12.5

7.36

5.25

0.56

12.75

7.52

5.5

0.66

13

8.51

5.75

0.76

13.5

9.53

6

0.84

14

10.49

6.25

0.93

15

12.89

6.5

1.03

16

16.06

6.75

1.24

 

FAQs on Diamond Weight Price Calculator with Steps

1. How much does a 1 carat diamond weight in grams?

One carat diamond weighs 1/5 grams (0.200 grams) or 0.007-ounce avoirdupois.

2. What is the weight of a 3 mm diamond?

The weight of a 3 mm diamond will be 0.10 carat or 0.1 grams.

3. Is a 1ct diamond big enough?

It may seem small but a 1-carat diamond is big enough to draw attention.

4. Is carat weight or size?

A “carat” is a weight measurement that equals 1/5 of 1 gram. So 1 carat will be 0.200 grams.