Use this LoRa range calculator to estimate maximum communication distance from your link budget. It is designed for quick planning of point-to-point LoRa and LoRaWAN-style deployments.
LoRa Range Calculator
How this LoRa range estimate works
This tool uses a link-budget approach with free-space path loss (FSPL). In plain terms, the calculator compares how much signal you can afford to lose against how much signal is typically lost over distance. If the received signal stays above receiver sensitivity plus fade margin, the link is considered possible.
Core formula
Theoretical maximum path loss:
Max Path Loss = TX Power + TX Gain + RX Gain − TX Loss − RX Loss − Environment Penalty − Other Losses − Fade Margin − Receiver Sensitivity
Free-space path loss in dB:
FSPL = 32.44 + 20·log10(frequency in MHz) + 20·log10(distance in km)
The calculator solves this equation for distance, then also reports a radio-horizon estimate from antenna heights.
Input guide and practical defaults
Receiver sensitivity matters most
LoRa range is heavily influenced by spreading factor (SF), bandwidth (BW), coding rate, and receiver implementation. If you do not have measured sensitivity from your exact radio settings, use conservative values:
| Typical LoRa Profile | Approx Sensitivity |
|---|---|
| SF7 / 125 kHz | -123 dBm |
| SF9 / 125 kHz | -129 dBm |
| SF12 / 125 kHz | -137 dBm |
Fade margin recommendations
- 10 dB: short links, mostly open LOS, low risk tolerance.
- 15 dB: mixed suburban terrain and moderate reliability targets.
- 20+ dB: harsh environments, seasonal foliage changes, or mission-critical traffic.
Why real-world LoRa range can differ from calculations
A link budget gives a useful first estimate, but real deployments are impacted by terrain, diffraction, clutter, antenna placement quality, and duty-cycle constraints. LoRa can often decode below the visual noise floor, but non-line-of-sight paths still introduce significant variability.
- Buildings and trees can add 10 to 30+ dB of extra attenuation.
- Low antenna height can make the radio horizon the limiting factor.
- Poor antenna matching (high VSWR) silently reduces effective power.
- Interference from nearby devices lowers packet success even with strong RSSI.
Tips to improve LoRa range
1) Improve antenna system before increasing power
Better antenna placement usually beats brute-force TX power. Raise antennas, use low-loss coax, and maintain clear Fresnel zone where possible.
2) Tune modulation for sensitivity
Higher spreading factors and narrower bandwidth improve sensitivity and link budget, but increase airtime. In LoRaWAN, more airtime means lower network capacity and stricter duty-cycle pressure.
3) Keep legal compliance in mind
Regional rules define maximum EIRP, duty cycle, and channel usage. A technically strong link can still be illegal if transmit settings exceed local regulations.
Deployment workflow you can follow
- Start with conservative sensitivity and at least 15 dB margin.
- Estimate range with this calculator for your terrain type.
- Perform field tests with packet delivery ratio (PDR), not just RSSI.
- Adjust antenna height and location before changing firmware parameters.
- Finalize settings only after day/night and weather variation checks.
Bottom line
This LoRa range calculator is best used for planning, comparison, and sanity checks. Treat the output as a design target rather than a guaranteed distance. If your measured field results are below estimate, add more fade margin and review antenna and obstruction losses first.