Sound Doppler Frequency Calculator
Calculate the observed sound frequency for a moving source and observer with explicit signed velocities relative to the medium.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Use the classical sound-wave Doppler ratio with separate source and observer motion. Convert the ratio into hertz difference and musical cents.
Observed f=emitted f×(c+observer toward source)/(c−source toward observer)
Worked example
At sound speed 340 m/s, a source moving toward a stationary observer at 34 m/s makes a 1000 Hz tone appear at 1111.111… Hz.
Assumptions and input details
One-dimensional motion along the line connecting source and observer, velocities relative to a uniform stationary medium. Each signed speed is restricted to ±99% of the sound speed. No wind-field, supersonic shock, changing direction or relativistic light-wave calculation. Positive values mean approaching for each separately labelled field; use negative values for recession.
References: OpenStax: the Doppler effect
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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