Belt Tension Frequency Calculator

This estimates belt tension from the vibration frequency of a plucked belt span. It runs locally in your browser; audio is not uploaded anywhere.

Inputs

Target tension, lbf

Free span length, inches

Whole belt weight, oz

Whole belt loop length, inches

Measured frequency, Hz

Optional known belt weight, lb/ft

Current frequency: -- Hz

Tap Start, allow microphone access, hold the phone near the belt span, then pluck the belt.

Belt weight per length: -- lb/ft

Target frequency: -- Hz

Calculated tension from measured Hz: -- lbf

Enter or capture a measured frequency to compare.

T = 4 W L² f² / g

T = belt tension in lbf, W = belt weight per length in lb/ft, L = free span in ft, f = frequency in Hz, g = 32.174 ft/s².

To get W from a whole belt: W = (belt weight oz / 16) / (belt length inches / 12).