Free Space Path Loss Calculator
Calculate free space path loss for a wireless RF link from frequency and distance using this free link budget calculator in your browser.
100% FreeRuns in your browserIntermediate
Enter Values
Minimum 0
Enter your values and press Calculate to see results.
How to use this calculator
- Enter the distance (km) and frequency (MHz).
- Read the path loss in dB.
How it works
FSPL (dB) = 20·log₁₀(distance km) + 20·log₁₀(frequency MHz) + 32.45.
Worked example
10 km at 2400 MHz. ≈ 120 dB.
Common mistakes
- Treating it as total loss — real links also lose to obstacles, rain and foliage.
- Mixing up MHz and GHz.
Frequently asked questions
What is free-space path loss?
The signal weakening from spreading out over distance in clear line-of-sight — the best case for a radio link.
Related tools
- Coax Cable Loss Calculator
- VSWR Calculator
- dBm to Watts Converter
- EIRP Calculator
- Link Margin Calculator
- Repeater Coverage Radius Estimator
Explore more in Telecommunications & Radio.
Cite this tool
Zerdly. (2026). Free Space Path Loss Calculator. Retrieved from https://www.zerdly.com/tools/free-space-path-loss-calculator/
Tip: Enter any known values to calculate the remaining results.
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