Work out lora range estimate instantly with clear inputs, formula shown and shareable results.
LoRa's long range comes from receiver sensitivity around -137 dBm at spreading factor 12, giving a link budget over 150 dB. Range then depends entirely on the path loss exponent of the environment: 2 in free space, 3 in suburban clutter and 4 or more indoors, which is why the same radio reaches 15 km rurally and 1 km in a city.
Log-distance path loss
budget = Ptx - sensitivity - fade margin; range from budget = L0 + 10 n log10(d)
Chirp spread spectrum lets the receiver decode signals well below the noise floor, buying about 20 dB over conventional narrowband FSK at the cost of data rate.
Higher SF improves sensitivity by roughly 2.5 dB per step but doubles the time on air, cutting throughput and increasing duty-cycle restrictions.