Carat is weight
Two diamonds with the same carat can face up differently because depth, cut style, and proportions change the visible spread.
Diamond Education
Diamond Size Chart
Compare carat weight with approximate face-up millimeter size across the most requested diamond cuts. Use this as a visual guide before confirming CAD dimensions, settings, and final stone availability.
MM to carat guide
Round Diamond Size Chart
| Carat Weight | Approx. MM Size | Face-up Spread |
|---|---|---|
| 0.25 ct | 4.0 mm | 4 mm |
| 0.50 ct | 5.1 mm | 5.1 mm |
| 0.75 ct | 5.8 mm | 5.8 mm |
| 1.00 ct | 6.5 mm | 6.5 mm |
| 1.50 ct | 7.4 mm | 7.4 mm |
| 2.00 ct | 8.2 mm | 8.2 mm |
| 3.00 ct | 9.3 mm | 9.3 mm |
| 4.00 ct | 10.2 mm | 10.2 mm |
| 5.00 ct | 11.0 mm | 11 mm |
Cut picture guide
All main diamond cuts
Each cut carries weight differently. Elongated cuts like oval, pear, emerald, and marquise often look larger from the top, while step cuts can show clarity more openly than brilliant cuts.
MM is the visual cue
For custom CAD work, millimeter dimensions help customers understand how large the stone will look in the setting.
Confirm before setting
Final stone selection should be checked against certificate dimensions, CAD scale, finger size, and setting design.