Link Budget Calculator

The Link Budget Calculator helps RF engineers, wireless network designers, satellite communication specialists, microwave engineers, telecommunications professionals, and students analyse the performance of radio communication links. By entering the operating frequency, transmission distance, transmitter power, antenna gains, feed-line losses, and additional system losses, the calculator determines wavelength, free-space path loss (FSPL), effective isotropic radiated power (EIRP), total antenna gain, total system loss, and received signal power. It is widely used for cellular networks, microwave backhaul, satellite communication, Wi-Fi, LoRaWAN, IoT deployments, point-to-point wireless links, and radio system planning.

Enter Frequency, Distance, Transmit Power, Transmit Antenna Gain, Receive Antenna Gain, Tx Feedline Loss, Rx Feedline Loss, Additional System Loss exactly in the units shown by this link budget. Check the operating band, unit prefix, and decimal position before calculating; these are the inputs used by the formula.

• Frequency — use MHz.
• Distance — use km.
• Transmit Power — use dBm.
• Transmit Antenna Gain — use dBi.
• Receive Antenna Gain — use dBi.
• Tx Feedline Loss — use dB.
• Rx Feedline Loss — use dB.
• Additional System Loss — use dB.

The results describe the calculated link budget values for the inputs you entered. Check each value against the available space, selected components, feed system, and operating conditions before making a final design decision.

The Link Budget uses Pr = Pt + Gt + Gr − FSPL − Losses. Supply Frequency (MHz), Distance (km), Transmit Power (dBm), Transmit Antenna Gain (dBi), Receive Antenna Gain (dBi), Tx Feedline Loss (dB), Rx Feedline Loss (dB), Additional System Loss (dB) in the displayed units, then use the calculated values as the first engineering target for this link budget & rf design or analysis.

A link budget is a complete accounting of all gains and losses experienced by a radio signal as it travels from the transmitter to the receiver. It is one of the most important calculations in RF engineering because it determines whether a wireless link will operate reliably under expected conditions. The received signal level depends on transmitter output power, antenna gain, feed-line losses, propagation loss, system losses, and receiver sensitivity. Although this calculator uses the standard free-space path loss (FSPL) model, practical wireless links are also influenced by atmospheric absorption, rain fade, multipath propagation, diffraction, terrain, foliage, building penetration, antenna alignment, cable quality, connector losses, and regulatory EIRP limitations. Engineers should also include an adequate fade margin to maintain reliable communication under changing environmental conditions.

Use the calculated link budget as the initial engineering estimate before deploying a wireless communication system. Verify transmitter output power, antenna gain, cable attenuation, connector losses, and receiver sensitivity using calibrated measurement equipment. Measure return loss (S11), VSWR, and antenna performance with a vector network analyser (VNA), and confirm transmitted and received signal levels using a spectrum analyser or power meter. For long-distance microwave and satellite links, include rain attenuation, atmospheric losses, Fresnel zone clearance, and fade margin in the final design. Simulation software such as Pathloss, Radio Mobile, CST Studio Suite, HFSS, or FEKO can further improve prediction accuracy before installation.