The image below shows the spreadsheet available here which also shows the center frequencies for each 20 MHz channel in 24 GHz and 5 GHz. Frequency Hz Wave velocity ms Wavelength m Wave velocity represents the speed of the wave. The formula for wavelength is l m c f l c f wave speed c ms frequency f Hz.
The unit hertz Hz was once called cps cycles per second.
V f l. Putting these figures without commas into the calculator above shows that we need. Wavelength l 700 nm Velocity of light v 3 x 108 ms. T period 1 f frequency.