Free · Waves and acoustics calculators 🔊

Frequency from Wavelength & Wave Speed

Convert between wavelength and frequency using a medium preset or your own positive phase speed.

  • Formula & worked example
  • Private in your browser
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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Private by default

Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

At wave speed 343 m/s, a wavelength of 0.5 m corresponds to frequency 686 Hz.

Frequency = phase speed / wavelength

Worked example

Enter these known values and leave the other values blank.

Medium speed preset or Custom
sound in air at 20 °C
Wavelength
0.5 m
Wave phase speed
343 m/s
Wave frequency
686 Hz

Assumptions and limitations

  • Wave speed, frequency and wavelength are positive. Use phase speed for the medium and frequency in question.
  • Presets retain fixed illustrative speeds. Actual values can depend on temperature, composition, wave mode and dispersion; choose Custom for a suitable value.
  • Changing wavelength units does not change the physical wavelength. Vacuum light speed is exactly 299,792,458 m/s.

Common questions

Can the same frequency have different wavelengths?

Yes. When speed changes between media, wavelength changes with it for the same frequency.

Can I supply a measured wave speed?

Choose Custom and enter the positive phase speed with the appropriate speed unit.

References

The calculation equations, inverse formulas, units, and input rules were imported from this source. Bookify provides the interface and equation solver.

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