🚓 Doppler Effect Calculator

What the Doppler effect is

The Doppler effect is the change in observed frequency of a wave caused by relative motion between the source and the observer. Approaching sources or observers raise the observed frequency (higher pitch for sound), while receding motion lowers it. The general formula is f’ = f·(v + v_o) / (v – v_s), where v is the wave speed in the medium, v_s is source velocity (positive toward the observer), and v_o is observer velocity (positive toward the source).

How this calculator works

Enter the source’s original frequency, the speed of the wave in its medium (343 m/s for sound in air at room temperature), and the velocities of the source and observer using the sign convention that positive means moving toward the other party. The calculator applies the Doppler formula to compute the observed frequency and the shift from the original.

This formula applies to sound waves in a medium; the relativistic Doppler effect for light uses a different equation. If the source travels at or faster than the wave speed, the classical formula breaks down, which this calculator guards against. For general educational purposes.