Blower Belt & Pulley Calculator
Start with what you already have, or let us guide a new setup. You will always verify the center-to-center measurement before using the recommendation.
Find your current blower drive ratio
Enter the tooth count on your existing pulleys. The crank pulley is the bottom pulley; the blower pulley is the top pulley.
Identify your blower-pulley style
Tap or click a photo to zoom in. Tooth spacing identifies the pitch, but the tooth profile still matters: GT and HTD belts/pulleys are not interchangeable.
If you still are not sure: measure the pitch
Measure from the same point on one tooth to the same point 10 teeth away, then divide by 10. This is more accurate than measuring just one tooth gap.
| Pitch | One tooth-tooth pitch | 10-pitch measurement |
|---|---|---|
| 1/2 in cog | 0.500 in / 12.7 mm | 5.000 in / 127 mm |
| 8 mm | 0.315 in / 8.0 mm | 3.150 in / 80 mm |
| 11 mm | 0.433 in / 11.0 mm | 4.331 in / 110 mm |
| 13.9 mm | 0.547 in / 13.9 mm | 5.472 in / 139 mm |
| 14 mm | 0.551 in / 14.0 mm | 5.512 in / 140 mm |
Your setup
Recommended combination
8mm HTDHow the calculation works
The tool uses the same maximum-tooth method as the GVM worksheet: max pulley teeth = 2 × (belt teeth − 2 × center distance in mm ÷ belt pitch). It only recommends belts where the pulley total falls inside the adjustment window for your selected idler bracket.
Suggested crank-pulley tooth count is mathematical. Confirm pulley alignment, idler adjustment, belt width, and the current GVM catalog before ordering.