Free-Space Link Budget Calculator (Friis)
Free-space path loss, EIRP and received power of a radio link from transmit power, antenna gains, frequency and distance.
How to use the Free-Space Link Budget Calculator
- Enter or select: Transmit power, Transmit antenna gain, Receive antenna gain, Frequency, Distance, Other losses (cables, polarisation…).
- The results (Wavelength, Free-space path loss, EIRP, Received power) are calculated instantly as you type.
- Use “Copy link” to share the calculation with the same input values.
Formula
- Pr = Pt + Gt + Gr − FSPL − L (dB)
- FSPL = 20·log₁₀(4πd/λ)
- = 20log₁₀d(km) + 20log₁₀f(MHz) + 32.44