Carat Weight
What is diamond carat weight?
Before grams and ounces, diamonds were weighed using carobs, a long green bean with seeds inside. The beans were nearly identical in size, making them ideal for Mediterranean traders to use when weighing gemstones. One seed equalled one carob, which is likely where the term carat originates.
Carat is often confused with the size of a diamond even though it’s actually a unit that measures its weight. Today, one carat is equal to 0.2 grams.
How does diamond carat weight impact price?
Because larger diamonds are more rare, the heavier the diamond, the higher the price.
Though price increases aren’t steady—they can increase exponentially with carat weight. For example, a 1 carat diamond would be valued higher than two 0.50 carat diamonds of the same quality.
In general, a doubling the size of your diamond can cost three to four times more.
Highly sought-after diamond sizes can also carry a price premium. If you’re after a 1, 1.5 or 2 carat etc. we recommend buying just shy of these carat weights, which can result in savings.
You can often save around 10% by choosing a diamond that is around 0.10cts lower than the popular sizes. They’ll appear almost identical in size but won’t carry the same price tag.
Nikolay Piriankov, CEO
So does bigger mean better when it comes to diamonds?
Just because a diamond is bigger, doesn’t mean it’s better.
The right diamond isn’t just based on one factor but a combination of all 4 Cs (carat, cut, clarity and color). When choosing a diamond, focus on the quality that’s most important to you, then work to balance the remaining three.
What do different carat weight diamonds look like?
Carat weight size chart
While carat weight is a measure of a diamond’s weight, and not its size, it is a consistent indicator of how large a diamond will look, when viewed from the top. Play around with our carat weight widget below to see how different carat weights look in different shapes and styles.
Top Tip
If you’re keen to stick within a set price point, it’s worth noting that diamonds of the same carat weight, but of a different shape will be priced differently.
For example, round diamonds carry a premium over other shapes because they produce the most waste in their cutting process.
Elongated diamond shapes like the marquise, oval and pear cut can appear larger in appearance, despite being the same carat weight.
Choosing a fancy shape will often provide you with better value than choosing a much sought-after round diamond.
The chart below shows the prices of a one carat G colour grade, VS2 clarity grade diamond in various shapes. These prices will increase on average should you increase the quality grades of the diamond and decrease on average should you decrease the quality grades of the diamond.
| Shape | Carat Weight | Price |
|---|---|---|
Round | 1.00 | £5,796 |
Oval | 1.00 | £4,773 |
Princess | 1.00 | £4,272 |
Marquise | 1.00 | £5,206 |
Cushion | 1.00 | £3,382 |
Emerald | 1.00 | £3,568 |
Pear | 1.00 | £4,783 |
A 0.90ct diamond can be 10-20% better value than a 1.0ct diamond of the same quality but can appear almost identical in size but very different in price.
What is the average carat weight for an engagement ring?
Amongst our customers, we see an average carat weight of around 0.79ct.
Colored gemstones often provide slightly better value for money, resulting in an average carat weight for colored gemstones averaging at around 0.96ct.