mechanical calculator
V-Belt Length Calculator
Estimate the belt length needed for a two-pulley drive from the pulley diameters and center distance.
How it works
L = 2C + (pi/2)(D1 + D2) + (D2 - D1)^2 / (4C).
Worked example
4 in and 8 in pulleys, 20 in centers: L = 40 + 18.85 + 0.2 = 59.05 in.
When to use it
- Round up to the nearest stock belt length.
- Center distance is measured shaft-center to shaft-center.