Work out wavelength to frequency (radio) instantly with clear inputs, formula shown and shareable results.
Wavelength times frequency equals the propagation speed, so lambda = c/f. In free space 300 MHz corresponds to 1 metre, giving the useful shortcut that wavelength in metres is roughly 300 divided by frequency in MHz. Inside a cable or dielectric the velocity factor shortens the wavelength proportionally.
Wavelength
lambda = c x velocity factor / f; in free space lambda(m) = 300 / f(MHz)
Electrical results are planning estimates only. Verify against the applicable wiring rules (IEC 60364, BS 7671, NEC or local code) and have all installation work designed and checked by a qualified electrician.
Signals travel slower in dielectrics, so a quarter-wave stub in coax with velocity factor 0.66 is a third shorter than its free-space length.
About 12.5 cm, which is why Wi-Fi antennas are small and why a quarter-wave element is only about 3 cm.