tools / RF & SDR
Wavelength and Frequency Converter
Convert any frequency to its wavelength in m, cm and mm, and read off the ITU band while you are at it. I use this constantly for sizing antennas, spacing elements, and sanity-checking a capture in an SDR.
Field trick: λ (m) ≈ 300 ⁄ f (MHz).
Wavelength3 m
Wavelength299.79 cm
Wavelength2,997.9 mm
ITU bandVHF
How it works
λ = c / f
Wavelength is the speed of light (299,792,458 m/s) over the frequency. The field shortcut: wavelength in metres is about 300 divided by the frequency in MHz.
FAQ
What is the wavelength of 2.4 GHz?
About 12.5 cm, which is why 2.4 GHz antennas and their roughly 3 cm quarter-wave elements are so small.
