

The princess cut is a square modified brilliant with sharp, uncut corners that deliver exceptional brilliance in a geometric silhouette. It's the most popular non-round shape and offers outstanding value, costing significantly less per carat than rounds.
Princess diamonds are known for very high brilliance with 57 facets. They're popular for engagement rings and channel-set bands. Here are the trade-offs.
A 1-carat princess diamond measures approximately 5.5 x 5.5 mm. Here are the most common sizes from 0.25 ct to 5 ct.
| Carat Weight | Size (mm) |
|---|---|
| 0.25 ct | 3.3 x 3.3 mm |
| 0.33 ct | 3.6 x 3.6 mm |
| 0.5 ct | 4.2 x 4.2 mm |
| 0.75 ct | 4.9 x 4.9 mm |
| 1 ct | 5.5 x 5.5 mm |
| 1.25 ct | 5.9 x 5.9 mm |
| 1.5 ct | 6.3 x 6.3 mm |
| 2 ct | 7.0 x 7.0 mm |
| 2.5 ct | 7.5 x 7.5 mm |
| 3 ct | 7.9 x 7.9 mm |
| 4 ct | 8.7 x 8.7 mm |
| 5 ct | 9.3 x 9.3 mm |
View full princess size chart → with all sizes from melee to 5+ carats.
Princess diamonds are priced at 25-35% less than round brilliant. Price depends on carat weight, color, clarity, and cut quality. For a personalized estimate, use our diamond price estimator.
Estimate princess diamond price →Last updated: 2026-07-16