Free Doppler Frequency Calculator
Calculate the observed frequency due to the Doppler effect: f_obs = f_source * (c + v_observer) / (c + v_source), with sign convention for approach/recession.
Hz
m/s
m/s
m/s
Observed Frequency
404.6113 Hz
Frequency Shift-35.3887 Hz
Observed Frequency vs Source Frequency
Doppler Effect for Sound
The Doppler effect shifts the observed frequency when the source or observer is moving relative to the medium.
Formula
f_obs = f_s * (c + v_obs) / (c + v_src)
Sign convention: v_obs is positive when moving toward the source; v_src is positive when moving away from the observer.
Example Calculation
A 440 Hz siren moves away at 30 m/s, observer stationary.
- 01f_obs = 440 * (343 + 0) / (343 + 30)
- 02f_obs = 440 * 343 / 373
- 03f_obs = 440 * 0.9196
- 04f_obs = 404.6 Hz (lower pitch)
Frequently Asked Questions
Learn More
Understanding Newton's Laws of Motion
A comprehensive guide to Newton's three laws of motion. Learn about inertia, force and acceleration, action-reaction pairs, and how these principles govern everyday physics.