Data Transfer Coverage Radius Calculator

1. Enter transmitter output

Provide transmitter power in dBm for the operating mode being evaluated.

2. Enter antenna gains

Add transmit and receive antenna gains in dBi for the installed antenna configuration.

3. Subtract fixed losses

Enter feeder, connector, splitter, or other fixed system losses in dB.

4. Set receiver threshold

Use the receiver sensitivity or minimum receive level appropriate to the data rate and modulation you need.

5. Reserve fade margin

Enter extra dB of margin for variation rather than designing exactly to the receive threshold.

6. Set frequency

Enter operating frequency in MHz. The result shows the theoretical free-space radius for the resulting path-loss budget.

Maximum path loss (dB) = TX power + TX gain + RX gain − System losses − Receiver sensitivity − Fade margin Distance (km) = 10^((Maximum path loss − 32.44 − 20 log10(Frequency MHz)) / 20)

TX power — Conducted transmitter power in dBm.

TX/RX gain — Antenna gains in dBi.

System losses — Fixed RF losses in dB.

Receiver sensitivity — Minimum receive level in dBm for the selected data mode.

Fade margin — Additional link margin in dB.

Frequency — Operating frequency in MHz.

Assumptions: The model uses free-space propagation. It does not include obstruction loss, Fresnel-zone blockage, diffraction, multipath fading, interference, weather effects, antenna height, or regulatory constraints.

What the result means

Use the main result as a planning estimate under the assumptions and inputs shown above.

For production decisions, compare the estimate with measurements and system-specific limits.

Given

• TX power: 23 dBm
• TX antenna gain: 8 dBi
• RX antenna gain: 8 dBi
• System losses: 3 dB
• Receiver sensitivity: −90 dBm
• Fade margin: 15 dB
• Frequency: 2,400 MHz

Calculation
Maximum path loss = 23 + 8 + 8 − 3 − (−90) − 15 = 111 dB
Distance = 10^((111 − 32.44 − 20 log10(2400)) / 20)
Distance ≈ 3.53 km

Result
about 3.53 km theoretical radius

The result is an ideal free-space baseline. A real data link should be engineered for the actual terrain, clearance, interference, and required throughput.