How far will it reach?

Estimate a LoRa link from power, antennas, settings and antenna height. It gives the best case for your setup; real terrain decides the rest.

FREQUENCYTX POWERdBm

TX ANTENNA GAINdBiRX ANTENNA GAINdBi

SPREADING FACTORBANDWIDTH

ANTENNA A HEIGHTmANTENNA B HEIGHTm

FADE MARGIN20 dBAllowance for trees, bodies, buildings and weather. 10 dB for open ground, 20–30 dB for forest or town.

ESTIMATED RANGE18 km

LINK BUDGET158 dB

RX SENSITIVITY-132 dBm

RADIO HORIZON18.1 km

FREE-SPACE LIMIT207 km

Height is your limit: the Earth's curve cuts the link at 18.1 km. Raise either antenna to go further. Keep about 40 m clear around the midpoint of the path.

/ HOW IT WORKS

Link budget

Transmit power plus both antenna gains, minus receiver sensitivity. Sensitivity comes from bandwidth, a 6 dB noise figure and the SNR each spreading factor can decode.

Two limits

The free-space limit is how far the budget stretches after your fade margin. The radio horizon is where the Earth's curve blocks the path, using standard 4/3 refraction. You get the smaller of the two.

Height beats power

Doubling power adds 6 dB. Putting one antenna 10 m higher can add many kilometres of horizon and clear the Fresnel zone over trees and roofs.

/ MORE TOOLS

SF · BW · CRLoRa airtimeTime on air, bit rate and how many packets the duty cycle allows, for any preset.mAh · mA · daysBattery lifeHow many days a node lasts from capacity, draw, traffic and solar.MHz · % · dBmFrequency regionsWhich LoRa band, duty cycle and power limit apply where you are.