Free · Acoustic waves calculators 🔊

Wave Frequency, Wavelength & Medium Speed

Convert frequency and wavelength using a selected reference wave speed or a custom positive speed.

  • Formula & worked example
  • Private in your browser
  • No signup
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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 a speed of 343 m/s, a 1,000 Hz sound wave has wavelength 0.343 m. The vacuum-light preset instead uses exactly 299,792,458 m/s.

Wavelength = phase speed ÷ frequency; frequency = phase speed ÷ wavelength

Worked example

Enter these known values and leave the other values blank.

Wave frequency
299792458 Hz
Selected phase speed
299792458 m/s
Wavelength
1 m

Assumptions and limitations

  • Speed, frequency and wavelength must be positive. Use the phase speed applicable to the medium, wave type and frequency.
  • Only the vacuum-light speed is an exact physical constant here. The other presets are fixed representative speeds, not a model of temperature, pressure, composition, polarization or dispersion.
  • The sound-in-air presets use 343 m/s at 20 °C and 355 m/s at 40 °C. They do not adjust for humidity or other conditions.
  • Choose custom wave velocity to enter a measured or otherwise appropriate speed. A preset holds its speed fixed until you change the selection.

Common questions

Does frequency change when light enters another medium?

At a stationary interface, frequency is conserved while phase speed and wavelength change. Use the appropriate speed for the medium in which wavelength is required.

Are the glass and seawater presets universal?

No. They are representative fixed values. Actual speed depends on the material and conditions; choose custom speed when those details matter.

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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