Call Us!

1-800-576-4569

Email Us!

  1. FREE FedEx® Shipping on Every Order
  2. 60-Day "Worry Free" Returns

Diamond Carat

A diamond’s weight is measured in what is known as a “carat“, which is a small unit of measurement equal to 200 milligrams. The origins of “carat” as a measurement comes from carobs (as in, carob seeds), which provided the units of measurement in ancient cultures that would balance a diamond on a scale against carob seeds to assess its value. In 1913, the “carat” weight for diamonds was internationally adapted to create a consistency in diamond evaluation. (The word ‘Karat’, which is used to express the purity of gold, is not used in relation to diamonds.)

Carat is not a measure of a diamond’s size, since cutting a diamond to different proportions can affect its weight. But, generally, a diamond with higher carats is going to be larger than one with lower carats, also depending on the shape selected.

Here is a diagram that shows the relative size of various carat weights for a round-shaped diamond that is cut to the same proportions:

Carat Weight Scale

Carat

Note: the diamonds illustrated are not shown actual size.

The most important thing to remember when it comes to a diamond’s carat weight is that it is not the only factor that determines a diamond’s value. In other words, bigger does not necessarily mean better. Also, a diamond’s weight can be ‘hidden’ in different parts of the stone. Some shapes are wider and heavier, and others have less weight at the bottom of the stone in order to maximize the size at the top of the stone.

We do not believe that choosing your stone should be purely based on the highest carat-count in your budget. Instead, all four Cs -- Cut, Color, Clarity and Carat Weight -- must be balanced in order to arrive at a diamond that fits your budget and that will be the best stone for you. None of the 4Cs is mutually exclusive; your choices on how to balance them depends on your personal preferences and priorities, which is why Diamond Select’s Ring Builder and loose diamond finder tools allow you to explore various settings for each of the 4Cs.

Each diamond available through Diamond Select was weighed as part of its certification process. The diamond grading report, which is made by weighing an unmounted stone, will tell you the exact carat weight, to the nearest hundredth of a carat, for that particular diamond. Each Carat is divided into 100 parts called ‘points.’ Points in a fraction of one carat are measured within ranges, so that a 3/4 carat diamond (when 3/4 equals .75 points) will be considered a 3/4 carat if it is between .69 and .82 points.

Here is a table of size and weight ranges:

Diamonds are generally valued on a per-carat basis. For example, a diamond of exceptionally high quality may sell for $20,000 per carat, while one of lesser quality may sell for $1,000 per carat. Note that diamond values also increase disproportionately as the size of the stone increases. In other words, a two-carat stone will generally cost far more than twice per carat than a one-carat stone. Thus, as you take a stone of a particular cut, clarity and color and increase its carat weight, you could see significant increases in the price per carat.

Fractions

Diamonds are generally valued on a per-carat basis. For example, a diamond of exceptionally high quality may sell for $20,000 per carat, while one of lesser quality may sell for $1,000 per carat.  Note that diamond values also increase disproportionately as the size of the stone increases. In other words, a two-carat stone will generally cost far more than twice per carat than a one-carat stone.  Thus, as you take a stone of a particular cut, clarity and color and increase its carat weight, you could see significant increases in the price per carat.