Use the formula: wavelength = speed of wave / frequency
For electromagnetic waves in vacuum, use: wavelength = speed of light / frequency
Write it as: λ = c / f
λ = wavelength
c = 3.0 × 10^8 m/s
f = frequency in Hz
Divide the wave speed by the frequency to get wavelength
The result will be in meters when speed is in m/s and frequency is in Hz