EIRP Calculator
Calculate Effective Isotropic Radiated Power (EIRP), ERP, and net system gain.
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Inputs
Live
Math
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Related
Enter parameters and click Calculate to view results
Formula & Theory
EIRP(dBm)=Pt+Gt-L, ERP(dBm)=EIRP−2.15This formula is used to calculate antenna parameters for eirp calculator.
Overview
EIRP helps you calculate design values for a link budget & rf project from Transmitter Power, Antenna Gain, Feedline Loss. Calculate Effective Isotropic Radiated Power (EIRP), ERP, and net system gain. 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 Transmitter Power, Antenna Gain, Feedline Loss exactly in the units shown by this eirp. Check the operating band, unit prefix, and decimal position before calculating; these are the inputs used by the formula.
- Transmitter Power — use dBm.
- Antenna Gain — use dBi.
- Feedline Loss — use dB.
Output Guide
The results describe the calculated eirp 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 EIRP uses EIRP(dBm)=Pt+Gt-L, ERP(dBm)=EIRP−2.15. Supply Transmitter Power (dBm), Antenna Gain (dBi), Feedline 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 EIRP(dBm)=Pt+Gt-L, ERP(dBm)=EIRP−2.15. 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 eirp 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 EIRP calculate?
Calculate Effective Isotropic Radiated Power (EIRP), ERP, and net system gain. The calculation provides an initial design value based on Transmitter Power (dBm), Antenna Gain (dBi), Feedline Loss (dB).
Which inputs are needed for the EIRP?
Enter Transmitter Power (dBm), Antenna Gain (dBi), Feedline 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 eirp?
It follows EIRP(dBm)=Pt+Gt-L, ERP(dBm)=EIRP−2.15. 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 EIRP?
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.