Wireless Link Range

d = f(Ptx, Gtx, Grx, sensitivity, freq)

Quick answer

This calculator solves d = 10^((Ptx + Gtx + Grx − sensitivity − 32.44 − 20×log₁₀(f_MHz)) / 20) km for Range. With TX Power 0 dB, TX Antenna Gain 9 dB, RX Antenna Gain 19.8 dB, Receiver Sensitivity 0 dB, Frequency 10 MHz, the result is 65.77 m.

Calculator

Result
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Formula

d = 10^((Ptx + Gtx + Grx − sensitivity − 32.44 − 20×log₁₀(f_MHz)) / 20) km

Description

This formula estimates the maximum free-space communication range based on the Friis transmission equation rearranged to solve for distance. It accounts for transmit power, antenna gains on both ends, receiver sensitivity, and operating frequency. The result represents ideal line-of-sight range without obstructions, multipath, or atmospheric absorption. Real-world range is typically 30-70% of the free-space calculation due to ground reflections, building penetration losses, and fading margins.

Variables

  • d — Maximum range (m)
  • Ptx — Transmit power (dBm)
  • Gtx — Transmit antenna gain (dBi)
  • Grx — Receive antenna gain (dBi)
  • sensitivity — Receiver sensitivity threshold (dBm)
  • f — Operating frequency (Hz)

Practical Notes

Add a fade margin of 10-20 dB for reliable outdoor links and 20-30 dB for indoor environments. Higher frequencies experience greater free-space path loss, which is why sub-GHz bands like 433 MHz and 868 MHz achieve longer range than 2.4 GHz for the same power and antennas.

Symbols and units

Symbol Meaning Default unit Accepted units
d Range m mm, cm, m, km
Ptx TX Power dBm dB
Gtx TX Antenna Gain dBi dB
Grx RX Antenna Gain dBi dB
sensitivity Receiver Sensitivity dBm dB
f Frequency MHz Hz, kHz, MHz, GHz

Step by step

  1. 1. What you know: TX Power 0 dB, TX Antenna Gain 9 dB, RX Antenna Gain 19.8 dB, Receiver Sensitivity 0 dB, Frequency 10 MHz
  2. 2. The relation: d = 10^((Ptx + Gtx + Grx − sensitivity − 32.44 − 20×log₁₀(f_MHz)) / 20) km
  3. 3. Substitute: Ptx = 0 dB, Gtx = 9 dB, Grx = 19.8 dB, sensitivity = 0 dB, f = 10 MHz
  4. 4. Result: Range = 65.77 m

Worked examples

Minimum range

Given: TX Power -2 dB, TX Antenna Gain 0.2 dB, RX Antenna Gain 0.44 dB, Receiver Sensitivity -4.4 dB, Frequency 100 kHz

Result: Range = 0.3388 km

Low range

Given: TX Power -20 dB, TX Antenna Gain 2 dB, RX Antenna Gain 4.4 dB, Receiver Sensitivity -44 dB, Frequency 1 MHz

Result: Range = 0.7907 km

Typical

Given: TX Power 0 dB, TX Antenna Gain 9 dB, RX Antenna Gain 19.8 dB, Receiver Sensitivity 0 dB, Frequency 10 MHz

Result: Range = 65.77 m

High range

Given: TX Power 30 dB, TX Antenna Gain 20 dB, RX Antenna Gain 44 dB, Receiver Sensitivity 66 dB, Frequency 100 MHz

Result: Range = 5.998 m

Maximum range

Given: TX Power 300 dB, TX Antenna Gain 200 dB, RX Antenna Gain 440 dB, Receiver Sensitivity 660 dB, Frequency 1 GHz

Result: Range = 2.39 × 10⁹ km

The same result in other units

Unit Value
mm 65770
cm 6577
m 65.77
km 0.06577

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Frequently asked questions

How do you calculate Wireless Link Range?

Use d = 10^((Ptx + Gtx + Grx − sensitivity − 32.44 − 20×log₁₀(f_MHz)) / 20) km. With TX Power 0 dB, TX Antenna Gain 9 dB, RX Antenna Gain 19.8 dB, Receiver Sensitivity 0 dB, Frequency 10 MHz, Range works out to 65.77 m.

What is the formula for Wireless Link Range?

The formula is d = 10^((Ptx + Gtx + Grx − sensitivity − 32.44 − 20×log₁₀(f_MHz)) / 20) km. This formula estimates the maximum free-space communication range based on the Friis transmission equation rearranged to solve for distance.

What units does Wireless Link Range use?

Range is shown in mm, cm, m, km. Values are held in SI base units internally, so you can mix prefixes without converting by hand.

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