Link Budget Calculator

Summary

Enter transmitter power, antenna gains, frequency, and distance to compute path loss, received power, link margin, and SNR.

How it works

1. Enter the transmitter output power in dBm (or watts — the tool converts automatically).
2. Add transmit-side cable/connector losses and the transmit antenna gain in dBi.
3. Set the carrier frequency in MHz or GHz and the link distance in meters or kilometers.
4. Enter the receive antenna gain in dBi, receive-side cable losses, and receiver noise figure.
5. The tool computes free-space path loss using the Friis equation, then derives received power (Pr), thermal noise floor, and SNR.
6. Enter your receiver sensitivity to see the link margin — positive margin means a reliable link.

Use cases

• Verifying a Wi-Fi or LoRa outdoor link will close before deployment.
• Sizing antennas and estimating coverage radius for IoT sensor networks.
• Satellite link analysis for ground station and payload engineers.
• Cellular network planning — checking cell-edge received power against sensitivity.
• Validating RF budgets during PCB and system-level design reviews.
• Teaching RF engineering fundamentals in university courses.
• Amateur radio (ham) operators planning HF or microwave contacts.
• Drone and UAV communication link validation.

Frequently Asked Questions