Plan site radios with distance and frequency inputs. Add gains, losses, and receiver sensitivity values. Get path loss, received power, and margin instantly here.
Typical planning values for open areas and temporary site networks.
| Scenario | Distance | Frequency | TX Power | Gains | Other Loss | Sensitivity | What to watch |
|---|---|---|---|---|---|---|---|
| Crane-to-office link | 1.2 km | 2.4 GHz | 20 dBm | 5 dBi / 5 dBi | 2 dB | -90 dBm | Fresnel clearance and cable quality |
| Camera backhaul | 0.6 km | 5 GHz | 23 dBm | 12 dBi / 12 dBi | 3 dB | -85 dBm | Alignment accuracy and wind movement |
| Sensor gateway | 300 m | 915 MHz | 14 dBm | 2 dBi / 2 dBi | 2 dB | -105 dBm | Interference and mounting height |
This calculator uses the standard free-space attenuation model:
Link budget terms are then applied:
Free-space path loss (FSPL) is the baseline attenuation between two antennas with clear line of sight. On construction sites, it helps size radios for temporary offices, tower cranes, cameras, and telemetry gateways before you account for real clutter. Treat FSPL as the starting point of a complete link budget that also includes antenna gains, cable losses, fade margin, and receiver sensitivity.
FSPL increases with both distance and frequency, so a small change in either can materially reduce received power. Higher frequencies may offer wider channels and smaller antennas, but they penalize range. For planning, compare multiple bands using the same distance and target margin; this calculator lets you switch units and immediately see how dB loss shifts your expected receive level.
Even when the path is “free space,” antenna height and alignment determine whether the link stays clear of equipment and terrain. Use higher mounting to reduce obstruction risk and keep polarization consistent end-to-end. Antenna gain is not free power: higher gain narrows the beam, so verify pointing tolerances for moving structures. Record cable runs carefully because connector and feeder losses can erase gain benefits.
Construction environments change daily, so design for margin. A fade margin target (often 10–25 dB) helps absorb multipath, weather effects, and incidental blockage. Received power should exceed receiver sensitivity by at least your margin, but also watch interference: a strong interfering signal can reduce throughput even if the link “passes.” Use conservative assumptions and revisit them after on-site measurements.
Use a repeatable workflow: define endpoints, distance, frequency, and antenna/cable parameters; calculate FSPL and received power; confirm margin; then validate in the field with a spectrum scan and throughput test. Save CSV/PDF outputs for design records, safety reviews, and client handover. When conditions change, update only the affected inputs to keep an auditable history of link decisions.
A practical baseline for a short site link. Enter these values to reproduce a typical planning check.
| Distance | Frequency | TX Power | TX Gain | RX Gain | Total Extra Loss | Fade Margin | RX Sensitivity |
|---|---|---|---|---|---|---|---|
| 0.8 km | 2400 MHz | 20 dBm | 9 dBi | 9 dBi | 3 dB | 15 dB | -90 dBm |
Tip: After calculating, export CSV/PDF to capture assumptions for handover.
No. FSPL assumes a clear line-of-sight path in free space. Add extra losses to represent foliage, partial obstruction, site clutter, and any known attenuation from enclosures or temporary barriers.
Use whichever matches your survey data. Meters work well for short site links; kilometers for campus-scale links. The calculator converts units internally and reports the same path loss.
For the same distance, higher frequency produces greater FSPL because wavelength is shorter. Higher bands can still perform well if you use higher-gain antennas and maintain adequate margin.
Many temporary links aim for 10–25 dB depending on criticality and variability. Use larger margin for changing environments, long spans, or where downtime has safety or schedule impact.
Received power estimates what arrives at the receiver input after gains and losses. Compare it to receiver sensitivity to check link feasibility, then confirm with real measurements and throughput tests.
Yes. Even short coax runs and multiple connectors add measurable loss. Enter TX/RX cable loss and any additional losses so your predicted margin is not overly optimistic.
It’s a fast planning aid for baseline loss and link budget checks. For complex deployments, also model terrain, clutter, interference, channel width, and regulatory limits, then validate on-site.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.