Doppler Effect Calculator

About this calculator

This calculator finds the observed frequency shift caused by the Doppler effect for sound, using f' = f × (v ± v_observer) / (v ∓ v_source), where v is the speed of sound in the medium. It shows how the frequency you hear changes depending on whether the source and observer are moving toward or away from each other.

Physics students use it to check homework on wave motion, and it's the same effect behind a passing ambulance siren changing pitch or a police radar gun measuring vehicle speed. Enter the source frequency, the speed of sound, and the velocities involved to see the shifted frequency.