Free Space Path Loss Calculator

Find radio signal loss over a free-space path.

Distance

Frequency (GHz)

Path loss (dB) 120.05

Formula: FSPL = 20·log₁₀(d) + 20·log₁₀(f) + 92.45

Step-by-step with your numbers:

1. Values used:

2. Distance = 10

3. Frequency = 2.4 GHz

5. Path loss = 120.05dB

Did we solve your problem today?

Free-space path loss is how much a radio signal weakens over distance with no obstacles.

The math behind it

FSPL(dB) = 20·log₁₀(d_km) + 20·log₁₀(f_GHz) + 92.45. Loss rises with both distance and frequency.

10 km at 2.4 GHz → about 120 dB.

Why do higher frequencies lose more?

Their shorter wavelengths capture less energy at the receive antenna.