Link Budget Calculator

Information and Tips
Wireless link budget diagram showing signal transmission between two rooftop antennas with TX power, antenna gains, cable losses and path loss over distance

Link Budget Calculator

The Link Budget Calculator helps estimate the expected received signal level of a wireless link. It is useful for point-to-point radio links, outdoor Wi-Fi bridges, industrial wireless networks and antenna system planning.

The calculator includes transmitter power, antenna gains, cable losses, distance, frequency and receiver sensitivity. The result shows the estimated received signal level and the link margin.

Calculate Wireless Link Budget





The result is a theoretical estimation. Real performance also depends on Fresnel zone clearance, reflections, interference, antenna alignment, polarization, weather conditions and radio hardware quality.

Formula

Received signal = TX power + TX antenna gain - TX cable loss - FSPL + RX antenna gain - RX cable loss - additional losses
FSPL = 32.44 + 20 × log10(distance in km) + 20 × log10(frequency in MHz)

The link margin is the difference between the estimated received signal level and the receiver sensitivity. A larger margin usually means a more stable wireless link.

How to Interpret the Result

Link margin Interpretation
20 dB or more Excellent margin for a stable link
10–20 dB Good margin for many practical installations
3–10 dB Risk area: the link may be unstable in real conditions
Below 3 dB Fail or very poor margin

Practical Notes

A link budget calculation is one of the first steps in planning a radio link. However, a strong theoretical signal level does not guarantee good performance if the Fresnel zone is blocked or if there is strong interference.

For outdoor point-to-point links, always check the Fresnel zone clearance, antenna alignment and local noise level. For reliable operation, the calculated link margin should not be too small.

  • Polski