To calculate the number of beads per inch:
Number of inches times 25.4mm = Length in mm
Length in mm divided by bead size (in mm) = Number of Beads per Inch
Beads per Inch Table
| Bead Size | Beads/Inch | Beads/16" |
| 3mm | 8.25 | 132 |
| 4mm | 6.25 | 100 |
| 5mm | 5.0 | 82 |
| 6mm | 4.25 | 68 |
| 7mm | 3.5 | 57 |
| 8mm | 3.3 | 50 |
| 9mm | 2.8 | 45 |
| 10mm | 2.5 | 41 |
| 11mm | 2.3 | 36 |
| 12mm | 2.0 | 34 |
| 14mm | 1.75 | 29 |
| 16mm | 1.5 | 26 |
| 18mm | 1.3 | 23 |
| 20mm | 1.2 | 20 |