Drive Belt Length Calculator
Calculate belt length for two-pulley systems or determine sizing for custom configurations.
Common Serpentine Belt Sizes
| Part # | Length | Ribs |
|---|---|---|
| K060820 | 82.0" | 6 |
| K060850 | 85.0" | 6 |
| K060880 | 88.0" | 6 |
| K060900 | 90.0" | 6 |
| K060930 | 93.0" | 6 |
| K060960 | 96.0" | 6 |
K06=6 ribs, K07=7 ribs. Last 3-4 digits = length in tenths.
Belt Length Formulas
Two Pulley Calculation
For two pulleys of different sizes:
L = 2C + 1.57(D + d) + (D - d)^2 / (4C)
Where: L = belt length, C = center distance, D = large pulley dia, d = small pulley dia
Belt Sizing Tips
- New belts stretch 1-2% during break-in
- Automatic tensioners compensate for wear
- Match rib count to OE specification
- EPDM belts last longer than neoprene
- Check tensioner pulley and idler bearings