Home › Mechanical & Drives › Power transmission
Mechanical & Drives

Belt length calculator

Open-belt length and wrap angle from pulley sizes and centre distance.

mm
mm
mm

Calculating…

How it's calculated

L = 2C + π(D + d) ÷ 2 + (D − d)² ÷ 4C Wrap = 180° − 2 × asin((D − d) ÷ 2C)

Use pitch diameters for V-belts to get the pitch length, which is what belt sizes are based on. Choose the nearest standard length and then adjust the centre distance with the tensioner.