calc.engineer / RF & Antennas / FSPL
FSPL v1.0.0
Calculate free-space path loss (FSPL) in decibels using the ITU-R P.525 standard formula. Given a frequency in MHz and distance in kilometres, returns the expected signal attenuation in an ideal line-of-sight radio link with no obstacles, reflections, or atmospheric absorption. Also computes the RF wavelength. Use this to estimate baseline path loss before adding fade margins, antenna gains, or environmental corrections. Feeds directly into link_budget for full end-to-end analysis.
Fill in the inputs and Compute to see the structured result.
From an agent (MCP) or the API
curl -X POST https://calc.engineer/api/fspl \
-H "Content-Type: application/json" \
-d '{"freq_mhz": …, "dist_km": …}'MCP: connect to https://calc.engineer/mcp and call fspl.
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