AirCompDX

Belt Length & Pulley

All calculators
Formula
L = 2C + π(D+d)/2 + (D−d)² / 4C
Belt length
62.02in
≈ 5.17 ft
Pulley ratio
3.000
Large ÷ small
Driven RPM
583rpm
Compressor pump RPM

How to use this calculator

Find belt length from sheave diameters and center distance, plus target deflection.

  1. Enter the driver and driven sheave pitch diameters.
  2. Enter the center distance between shafts.
  3. Read the required belt pitch length and wrap angle.
  4. Set tension to the calculated deflection force at 1/64 in per inch of span.

Frequently asked questions

How do you calculate V-belt length?
L = 2C + 1.57(D + d) + (D − d)² ÷ (4C), where C is center distance and D and d are the sheave pitch diameters.
How tight should a compressor belt be?
Deflect the belt 1/64 in for every inch of span at the manufacturer's specified force — roughly 1/4 in of deflection on a 16 in span.
Why do belts wear out fast?
Misaligned sheaves, over- or under-tensioning, worn sheave grooves, and mixing old and new belts in a set are the usual causes.