Note: Calculates attenuation using the Friis transmission equation where FSPL = 20*log10(d) + 20*log10(f) + 32.44 for frequency in MHz and distance in km. This tool is for preliminary estimation only, not a substitute for review by a qualified/licensed engineer.
For RF network engineers doing first-pass point-to-point and satellite link planning who need a single FSPL number fast — this calculator provides instant free-space path loss (FSPL) calculations. It specifically uses distance in kilometres and frequency in megahertz, aligning with the 32.44 constant in the Friis transmission equation, which simplifies initial estimations for RF link budgets. This approach ensures consistent and reliable results for preliminary design stages.
The tool calculates attenuation using the Friis transmission equation where FSPL = 20*log10(d) + 20*log10(f) + 32.44 for frequency in MHz and distance in km, making it directly applicable to many common scenarios in wireless communication.
Q: What formula does this free space path loss calculator use?
A: FSPL (dB) = 20·log10(d) + 20·log10(f) + 32.44, with distance d in kilometres and frequency f in megahertz.
Q: How much does path loss increase if I double the distance or the frequency?
A: Each doubling of distance adds 20·log10(2) ≈ 6.02 dB, and each doubling of frequency adds another ≈ 6.02 dB, because both terms are logarithmic with the same 20 multiplier.
Q: Do I add or subtract antenna gain from path loss?
A: Subtract it — the calculator reports Net Loss = FSPL − Gtx − Grx, so a 24 dBi dish at each end removes 48 dB from the FSPL figure.
Q: Can I use this result to sign off a real link budget?
A: No — it is for preliminary estimation only and is not a substitute for review by a qualified or licensed engineer.