What is Carat?
Carat refers to the weight of a diamond. Diamonds are all weighed in metric carats rather than grams or ounces. This is a standard industry practice around the world.
Diamond is expressed to the hundredth of a carat. Carat weight of less than a carat is expressed in points. So, for example, a 0.75ct diamond will be 75 points. Most jewellers will refer to carat weight in this terminology.
Another way to explain this would be using pounds, 100 pence equals 1 whole pound. Therefore 50pts will be 0.50ct and so on.
How to Work Out Carat Weight?
A common misconception is that it refers to the physical size of a diamond, which is incorrect. The diamond weight does not govern the size of stone.
We always recommend trying a range of carat weight on to determine which will be best for you. This way you will also be able to assess the visible size. For those who can't come into our store to view diamonds we have the chart below to give you an indication on size.
| Carat Weight | 0.25ct | 0.50ct | 0.75ct | 1ct | 1.50ct | 2ct | 3ct | 4ct | 5ct | Carat Weight |
|---|---|---|---|---|---|---|---|---|---|---|
![]() | 4mm | 5mm | 5.50mm | 6.50mm | 7.50mm | 8mm | 9.40mm | 10.40mm | 11.20mm | ![]() |
![]() | 3.50mm | 4.50mm | 5mm | 5.50mm | 6.80mm | 7.50mm | 8mm | 8.90mm | 9.70mm | ![]() |
![]() | 4x4mm | 5x5mm | 6x6mm | 6.50x6.50mm | 7x7mm | 8x8mm | 9x9mm | 10x10mm | 11x11mm | ![]() |
![]() | 4x3mm | 6x4mm | 6.50x4.50mm | 7x5mm | 8x6mm | 8.50x6.50mm | 10x8mm | 11x9mm | 10x10mm | ![]() |
![]() | 3.70mm | 4.40mm | 5mm | 5.80mm | 6.40mm | 7mm | 8.10mm | 9mm | 9.60mm | ![]() |
![]() | 5x3mm | 8x4mm | 9x4.50mm | 10x4.75mm | 11x5mm | 12x6mm | 14x7mm | 15x7mm | 16x8mm | ![]() |
![]() | 3.50x3mm | 5x4.50mm | 5.50x5mm | 6x5.50mm | 7x6mm | 7.50x7mm | 8.50x7.50mm | 9.50x8.50mm | 10x9mm | ![]() |
![]() | 4x3.50mm | 5x4.50mm | 6x5mm | 6.50x5.50mm | 7.50x6.50mm | 8x7mm | 9x8mm | 10x8.50mm | 10x9.50mm | ![]() |
![]() | 5x3mm | 6x4mm | 7x5mm | 7.50x5.50mm | 8.50x6.50mm | 9x7mm | 10x8mm | 11x9mm | 12x10mm | ![]() |
![]() | 4x2mm | 6x4mm | 7x5mm | 8x5mm | 9x6mm | 10x7mm | 12x8mm | 14x9mm | 15x10mm | ![]() |









