LoRa Range Estimate Calculator

Work out lora range estimate instantly with clear inputs, formula shown and shareable results.

About LoRa Range Estimate Calculator

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.

Formula

Log-distance path loss

budget = Ptx - sensitivity - fade margin; range from budget = L0 + 10 n log10(d)

Worked example

With the default values below, LoRa Range Estimate Calculator returns Estimated range of 6.21. Change any input above and every figure here is recalculated in your browser.

Inputs used

Transmit power: 14 dBm
Receiver sensitivity: -137 dBm
Frequency: 868 MHz
Environmentone of Free space / line of sight, Rural, Suburban, Urban, Dense urban / indoor: Suburban

Results

Estimated range: 6.21 km
Link budget: 145.00 dB
Path loss exponent: 3.00
Fade margin assumed: 10.00 dB

Step by step

1Values used
2Log-distance path loss
3Estimated range= 6.21 km
4Link budget= 145.00 dB
5Path loss exponent= 3.00
6Fade margin assumed= 10.00 dB

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why does LoRa reach so far?

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.

What does spreading factor trade?

Higher SF improves sensitivity by roughly 2.5 dB per step but doubles the time on air, cutting throughput and increasing duty-cycle restrictions.