1 Carat Lab-Grown Diamond: Price Guide 2026
Quick Answer
How much does a 1 carat lab diamond cost?
A 1 carat lab-grown diamond (round, G color, VS2 clarity, IGI certified, Excellent cut) costs $650–$1,100 at major retailers. Clean Origin is consistently the best value; Brilliant Earth commands a premium for its brand and sustainability positioning. Natural 1ct diamonds cost $4,500–$8,000 for equivalent specs — lab diamonds save you 80–85%.
📊 1ct round G/VS2 IGI Excellent: $650–$1,100 lab-grown vs $4,500–$8,000 natural. #1 most searched carat weight globally.
2026 Price Comparison by Retailer
| Retailer | Round G/VS2 | Oval G/VS2 | Cushion G/VS2 | Emerald G/VS1 |
|---|---|---|---|---|
| Clean Origin | $650–$950 | $700–$1,000 | $620–$900 | $1,000–$1,350 |
| James Allen | $720–$1,050 | $780–$1,100 | $690–$980 | $1,050–$1,450 |
| Brilliant Earth | $880–$1,250 | $950–$1,380 | $840–$1,200 | $1,200–$1,600 |
| Blue Nile | $760–$1,100 | $820–$1,180 | $730–$1,050 | $1,100–$1,500 |
| VRAI | $900–$1,300 | $980–$1,400 | N/A | $1,250–$1,700 |
How Big Is a 1 Carat Lab Diamond?
A 1ct round brilliant measures approximately 6.5mm in diameter — roughly the size of a standard pencil eraser. Shape dimensions vary:
| Shape | Approximate Size (1ct) | Face-Up vs Round |
|---|---|---|
| Round | 6.5mm diameter | Baseline |
| Oval | 8.0 × 5.5mm | +10–15% larger face-up |
| Marquise | 10.5 × 5.5mm | +15% larger face-up |
| Pear | 8.5 × 5.5mm | +15–20% larger face-up |
| Cushion | 5.8 × 5.8mm | Similar to round |
| Emerald | 8.0 × 6.0mm | +8–10% larger face-up |
Best Grades for 1 Carat
At 1ct, grade choices matter more than at 0.5ct — the diamond is large enough that color warmth and inclusions become more noticeable.
- Color: G is the ideal sweet spot — faces up white, ~15% cheaper than F/E. H is fine in yellow or rose gold settings.
- Clarity: VS2 is the standard recommendation. SI1 can be eye-clean at 1ct but must be verified with 360° video. VS1+ is overkill.
- Cut: Always Excellent (or Ideal at James Allen). Cut is the most important factor for a round brilliant — don't compromise here.
- Certification: IGI is the standard for lab diamonds. GIA certified lab diamonds exist but are rarer and not necessarily better quality — just different certification.