Wavelength to Frequency Calculator
f = v ÷ λ • Preset or custom wave speed
Choose a preset or switch to custom speed.
Quick summary
Enter wavelength, then click Calculate.
Custom wave speed must be greater than 0.
Wavelength must be greater than 0.
Results
Frequency
— Hz
Wavelength
— m
Wave speed
— m/s
Results are calculated in SI units first.
Use this Wavelength to Frequency Calculator to calculate wave frequency from wavelength and wave speed.
Calculation Method
The basic wave relationship is:
v = f × λ
Rearranged for frequency:
f = v ÷ λ
Where f is frequency, v is wave speed, and λ is wavelength.
For electromagnetic radiation in vacuum:
v = c = 299,792,458 m/s
Example
For light with a vacuum wavelength of 500 nm:
500 nm = 5 × 10−7 m
f = 299,792,458 ÷ (5 × 10−7)
f ≈ 5.996 × 1014 Hz
This is approximately 599.6 THz.
Important Note
Wave speed depends on the wave and medium. For calculations in a medium such as air or water, use a wavelength and wave speed that refer to the same medium.