Sandpaper Grit Converter
Convert sandpaper grit numbers to micron particle size.
Look up CAMI and FEPA grit equivalents for woodworking and finishing.
Select a grit number — see the micron size and typical use.
Grit Details
Sandpaper grit numbers indicate the size of abrasive particles.
Higher grit = finer abrasive = smoother finish.
Common grit to micron conversions (CAMI standard):
| Grit | Microns | Use |
|---|---|---|
| 40 | 425 | Heavy material removal |
| 60 | 268 | Rough shaping |
| 80 | 190 | Initial sanding |
| 100 | 140 | General sanding |
| 120 | 115 | Smoothing before finish |
| 150 | 92 | Final sanding before paint |
| 180 | 78 | Between coats |
| 220 | 68 | Fine finish sanding |
| 320 | 46 | Very fine sanding |
| 400 | 35 | Wet sanding |
| 600 | 25 | Ultra fine, polishing |
| 1000 | 18 | Mirror finish |
| 2000 | 10 | Final polish |
Approximate formula:
- Microns = 25,400 / grit (rough approximation)
- Actual values vary by standard (CAMI vs FEPA/P-grade).