Last updated on October 9, 2020
When making an expensive purchase such as a diamond, it always makes sense to look for ways to save some money without buying a low-quality stone. This guide will help you to pick the right diamond carat weight and end up with a good stone at a reasonable price.
What is Diamond Carat Weight?
Carat weight (ct) is the unit of measurement for the physical weight of diamonds. It originates from the ancient method of weighting precious metals and gemstones against the seed of the carob tree. At the time carob seeds were considered to be even in weight and were used as weighting references by traders. As you could guess, carob seeds varied in sizes and the actual weight of the gems could vary by around one metric carat. It wasn’t until 1907, at the Fourth General Conference on Weights and Measures when it was agreed upon that one diamond carat would be equal to 200 milligrams or 0.2 grams.
Nowadays, carat weight is measured using a highly accurate and calibrated digital scale which is capable of measuring even extremely small weights.
In terms of gemstone weight, there is also a term “point”. A point is one-hundredth of a carat, and 100 points are equal to 1 carat.
It is important to understand that carat is not how large a diamond is, meaning two diamonds of the same carat weight may be quite different in size depending on their cut quality and shape.
Carat weight is one of the four main components (4 Cs) of a diamond along with colour, clarity and cut, that indicate the quality of the stone and determine its value. Diamond price increases with carat weight because larger diamonds are rarer and more desirable as a result. However, two diamonds of the same carat weight can vary in prices depending on the other three factors of the diamond and other pricing criteria.
How Can I Save Money on Diamond Carat Weight?

Since carat weight is one of the most important determinants of diamond prices, the value of stone goes up when carats increase. However, diamond prices jump sharply at popular carat weights because such carats are in higher demand. The most popular carat weights are round numbers (1ct, 2ct, 3ct, etc.) and their fractions (0.25ct, 0.50ct, 0.75ct, 1.50ct, etc.)
For example, if a D colour, IF clarity 0.45-carat round diamond costs $1,350 and a 0.46-carat stone of the same specifications costs $1,750, a 0.50-carat diamond will cost $2,350. As you can see the difference in price is significant.
The easiest way to save money on carats is to buy a diamond slightly below in-demand sizes. For example, instead of buying a 1-carat diamond, you may opt for a 0.95 – 0.98 one – its size will look the same to the naked and no one will notice the actual difference.
Keep in mind that diamonds rarely come in exact carat weights. For example, if you ask for a 1-carat diamond, the salesperson will show you stones that are slightly above or below that mark.
You should also remember that the higher the carat, the more the stone costs, meaning if you inquire about the exact carat weight, you should ask for carats that are slightly below the benchmark if you want to save some money.
Don’t Focus Blindly on Diamond Carats
While diamond carat is important, comparing the value of diamonds by their weight is like comparing the value of artworks by their size. For example, a wall-sized painting by an unskilled artist may be bigger than a miniature by Matisse, but it will never worth more.
Larger diamonds are rarer, but the increase in size is not always proportionate to the increase in value. Two diamonds of the equal carat weight may be unequal in quality and value as a result. For example, if a diamond is improperly cut, the added weight will only reduce its brilliance because a poor cut quality affects the way the stone reflects light. That is why it is always better to have a smaller excellent cut diamond than an improperly cut stone that is high in carat weight.