LoRa Range Estimator
“LoRa Range Estimator” is technically more accurate. Real-world range depends on terrain, obstacles, and interference — no single formula can predict actual coverage. What we can calculate is the theoretical free-space range.
Formula Explanation
The free-space range is derived from the Friis transmission equation:
Range (km) = 10((LinkBudget − 32.44 − 20 × log10(f)) / 20)
Where LinkBudget is calculated as:
LinkBudget = TXPower + TXGain + RXGain − RXSensitivity
The free-space path loss (FSPL) model assumes a direct line-of-sight path with no obstacles. This is an ideal scenario rarely found in real-world IoT deployments.
Reference: Free-Space Range by SF and Band
Assuming 20 dBm TX power, 2 dBi antennas.
| SF | Sensitivity | 433 MHz | 868 MHz | 915 MHz |
|---|---|---|---|---|
| SF7 | -123 dBm | 1234.6 km | 615.9 km | 584.2 km |
| SF8 | -126 dBm | 1743.9 km | 869.9 km | 825.2 km |
| SF9 | -129 dBm | 2463.3 km | 1228.8 km | 1165.7 km |
| SF10 | -132 dBm | 3479.5 km | 1735.7 km | 1646.6 km |
| SF11 | -134.5 dBm | 4639.9 km | 2314.6 km | 2195.7 km |
| SF12 | -137 dBm | 6187.5 km | 3086.6 km | 2928.1 km |