Diamond education
Princess cut engagement rings
A square with brilliant sparkle.
By the CTJ Jewellery team, led by founder Greg Ward · Updated September 2026 · Editorial policy
Key facts
- Square outline, pointed corners
- Brilliant faceting for strong sparkle
- Lower price per carat than round
- Protect the corners with V claws
- A ratio of 1.00 to 1.05 looks square
- Natural or lab-grown
Why do princess cuts cost less?
A princess cut keeps more of the rough diamond than a round, which loses more weight in cutting. Less waste means a lower price per carat for the same grades.
How big does a princess cut look?
A princess looks slightly smaller face-up than a round of the same weight, because more weight sits in its depth. Its corners give it a longer diagonal. A 1 carat princess measures about 5.5mm on each side.
Which ratio should I choose?
| Ratio | Look |
|---|---|
| 1.00 to 1.02 | Perfectly square |
| 1.02 to 1.05 | Square to most eyes |
| 1.05 and above | Slightly rectangular |
Best settings for a princess
- Four V claws on the corners
- Channel-set band for a clean line
- Halo for extra size
- Three stone with trapezoid or princess side stones