Free-Space Path Loss Calculator

Calculate ideal free-space path loss and wavelength from frequency and propagation distance.

INPUT

Enter frequency and distance

Specify the operating frequency and the free-space distance between the reference points.

Frequency Frequency must be greater than zero.

Frequency unit

Distance Distance must be greater than zero.

Distance unit

Results calculated for 1 GHz over 1 km.

CALCULATION METHOD

Equations

λ = c / f

FSPL = 20 log₁₀ (4 π d / λ)

FSPL_dB ≈ 32.4478 + 20 log₁₀(d_km) + 20 log₁₀(f_MHz)

c = 299,792,458 m/s

ENGINEERING USE

Review the stated assumptions

This calculator is an engineering aid. Confirm that its units, equations and assumptions are appropriate for the application before using the result in a design, test limit or specification.