A 2 carat round diamond measures about 8.11 mm across and covers roughly 51.6 mm² seen from above.
Carat is weight, not size, so the same 2 ct buys visibly different dimensions depending on shape. At this weight the gap between the shape that spreads widest (emerald) and the most compact (cushion) is about 24% of face-up area — for the same weight, and broadly the same price.
| Shape | Length × width (mm) | Face-up area (mm²) |
|---|---|---|
| Round | 8.11 × 8.11 | 51.6 |
| Oval | 9.97 × 7.12 | 55.8 |
| Cushion | 7.35 × 7.00 | 46.1 |
| Pear | 10.63 × 6.86 | 49.6 |
| Marquise | 12.30 × 6.48 | 55.9 |
| Emerald | 9.10 × 6.50 | 57.3 |
| Radiant | 8.06 × 6.71 | 52.1 |
| Princess | 6.91 × 6.91 | 47.8 |
| Asscher | 7.16 × 7.16 | 49.0 |
Face-up area is what the eye reads as "big". Two 2 ct stones can differ by a fifth in the area they cover while weighing exactly the same, because depth hides weight underneath, where nobody sees it.
A figure in millimetres is hard to picture, and photographs of other people's hands are worse than useless — the same stone on a slender finger looks like a bigger stone. This tool renders it at true millimetre scale on a photo of your hand, calibrated from your ring size or a bank card, so the size on screen is the real one. The photo is processed on your device and never uploaded.
See 2 ct on your own hand →