Free Space Path Loss (FSPL) Calculator
Use this tool to calculate free-space path loss without obstacles or reflections. Optional antenna gains are applied separately to show the resulting link loss.
Result will appear here
Result will appear here
Formula:
FSPL (dB) = 20 log10(d) + 20 log10(f) + 20 log10(4π/c)
Link loss = FSPL − GTx − GRx
Where:
- d = distance (in meters)
- f = frequency (in Hz)
- c = speed of light (3×108 m/s)
- GTx = transmitter antenna gain (in dBi)
- GRx = receiver antenna gain (in dBi)
This tool helps with:
Estimating RF signal strength loss in free space.
Predicting the impact of distance and frequency on signal propagation.
Accounting for antenna gain in both transmission and reception.
Understanding theoretical signal loss for propagation through open space.
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Last updated on September 24, 2026
Author: IBL-Editors Team
Technical Review: Andreas Bender - Deputy Managing Director | IBL-Lab GmbH Give feedback on this article
Author: IBL-Editors Team
Technical Review: Andreas Bender - Deputy Managing Director | IBL-Lab GmbH Give feedback on this article