Doppler Effect Calculator
What frequency is heard when source and listener move toward each other? Enter the stated inputs to calculate this model.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Sound speed (m/s) | Enter sound speed in m/s; use the same basis as the other measurements. |
| Emitted frequency (Hz) | Enter emitted frequency in Hz; use the same basis as the other measurements. |
| Listener speed toward source (m/s) | Enter listener speed toward source in m/s; use the same basis as the other measurements. |
| Source speed toward listener (m/s) | Enter source speed toward listener in m/s; use the same basis as the other measurements. |
Understanding your result
Read Observed frequency (Hz) in the units and model stated on this page. The formula frequency=f*(speed+listener)/(speed-source) defines the relationship; measurement accuracy and model applicability are separate from numerical precision.
Common mistakes
- Mixing input units or changing the physical meaning of a variable without changing the model.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
Calculation checks, sources and review limits
What frequency is heard when source and listener move toward each other?
What frequency is heard when source and listener move toward each other? Enter the stated inputs to calculate this model.
Common uses
- What frequency is heard when source and listener move toward each other
How it works
frequency=f*(speed+listener)/(speed-source)
Worked example
Enter Sound speed: 340 m/s; Emitted frequency: 1000 Hz; Listener speed toward source: 10 m/s; Source speed toward listener: 20 m/s. Results: Observed frequency: 1093.75 Hz.