Round Diamond Size Chart
Round brilliant diamonds are graded by diameter (across the widest point). This chart maps carat weight to approximate diameter in millimeters — a practical reference when shopping online.
| Carat | Diameter | Appearance |
|---|---|---|
| 0.25 ct | 4.1 mm | Delicate — ideal for minimalist designs |
| 0.50 ct | 5.1 mm | Subtle — popular for everyday rings |
| 0.75 ct | 5.8 mm | Balanced — noticeable without being bold |
| 1.00 ct | 6.5 mm | Classic — the most popular engagement size |
| 1.50 ct | 7.4 mm | Impressive — noticeably larger on the hand |
| 2.00 ct | 8.1 mm | Bold — a substantial statement piece |
| 2.50 ct | 8.8 mm | Show-stopping — luxury tier |
| 3.00 ct | 9.2 mm | Luxury — rare and highly coveted |
Important: Cut quality significantly impacts how large a diamond appears. A well-cut 0.90ct round diamond can look larger than a poorly-cut 1.00ct stone. Always prioritize cut grade when selecting a diamond.