Engineering & mechanics
Free-space radio path loss
Calculate ideal geometric radio loss from frequency and separation.
A clear answer. Here’s how.
Uses FSPL=20log10(4πd/λ), λ=c/f with c exactly 299,792,458 m/s. Reports wavelength too. This is a free-space far-field geometric loss, not a terrain or indoor propagation prediction. Antenna gains, cable loss, polarisation, obstructions, multipath, near-field coupling and receiver sensitivity must be considered separately.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Frequency (MHz)
- 2400
- Separation (km)
- 1
Example result
- Free-space path loss (dB)
- 100.052008056
- Wavelength (m)
- 0.124913524167