Link Budget Calculator
Calculate free-space path loss, EIRP, and received signal level for RF and wireless communication links.
8
Inputs
Live
Math
3
Related
Enter parameters and click Calculate to view results
Formula & Theory
Pr = Pt + Gt + Gr − FSPL − LossesThis formula is used to calculate antenna parameters for link budget calculator.
Overview
Link Budget helps you calculate design values for a link budget & rf project from Frequency, Distance, Transmit Power, Transmit Antenna Gain, Receive Antenna Gain, Tx Feedline Loss, Rx Feedline Loss, Additional System Loss. Calculate free-space path loss, EIRP, and received signal level for RF and wireless communication links. Use the result to make an informed first design decision before choosing hardware, setting dimensions, or evaluating the RF system in its final environment.
Input Guide
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.
Output Guide
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.
How This Calculator Works
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.
Design Notes
This link budget & rf calculation is based on Pr = Pt + Gt + Gr − FSPL − Losses. Real-world accuracy depends on factors such as material properties, losses, mounting, nearby conductors, ground interaction, feed-line effects, and construction tolerance. Confirm the final system with measurement or simulation.
Build and Tuning Notes
Apply the link budget result as an initial target, then validate it in the intended installation. Keep the physical layout and feed arrangement consistent while testing, change one parameter at a time, and record the measured outcome before making another adjustment.
Frequently Asked Questions
What does the Link Budget calculate?
Calculate free-space path loss, EIRP, and received signal level for RF and wireless communication links. The calculation provides an initial design value based on 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).
Which inputs are needed for the Link Budget?
Enter 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) using the displayed units. Each value directly affects the calculated result, so confirm the unit and operating conditions before running the calculation.
How accurate is this link budget?
It follows Pr = Pt + Gt + Gr − FSPL − Losses. It is accurate for the formula assumptions, but installed performance can change because of materials, loss, environment, mounting, nearby objects, and measurement uncertainty.
What should I do after using the Link Budget?
Compare the result with the practical constraints of your link budget & rf system, then validate the completed design with appropriate measurement equipment or simulation.
Alex Warren
B.Sc. in Electrical & Electronic Engineering (EEE)
Alex specialises in antenna design and wave propagation. His expertise helps ensure these calculators present practical RF concepts, useful design estimates, and clear engineering guidance for students, HAM operators, and wireless professionals.