Tools / rf-link-budget-calculator

RF Link Budget Calculator

Use this RF Link Budget Calculator to estimate EIRP, free space path loss (FSPL), received power, link margin, and pass or fail status for wireless links. It is useful for microwave links, WiFi bridges, cellular planning, satellite links, and general RF system design.

Calculate RF Link Budget

Tx Power (dBm)

Tx Antenna Gain (dBi)

Tx Cable Loss (dB)

Other Tx Losses (dB)

Frequency

Frequency Unit

Distance

Distance Unit

Rx Antenna Gain (dBi)

Rx Cable Loss (dB)

Other Rx Losses (dB)

Receiver Sensitivity (dBm)

Optional advanced inputs

Additional Path Losses (dB)

Required Fade Margin (dB)

These are optional. For a basic RF link budget, the main inputs are enough. Use advanced inputs when you want to include extra propagation losses or enforce a minimum design margin.

Result

Enter the RF system values to calculate the link budget.

EIRP -

FSPL -

Received Power -

Link Margin -

Pass / Fail -

RF Link Budget Formula

EIRP (dBm) = Tx Power + Tx Antenna Gain - Tx Cable Loss - Other Tx Losses

FSPL (dB) = 32.44 + 20 * log10(f_MHz) + 20 * log10(d_km)

Received Power (dBm) = EIRP - FSPL - Additional Path Losses + Rx Antenna Gain - Rx Cable Loss - Other Rx Losses

Link Margin (dB) = Received Power - Receiver Sensitivity

Pass if Link Margin >= Required Fade Margin

Do You Need Advanced Inputs?

No. For most users, the basic inputs are enough to estimate EIRP, FSPL, received power, and link margin.

Optional advanced inputs are helpful when you want a more realistic design check. For example, you may want to include extra path losses from connectors, atmospheric loss, rain fade, body loss, radome loss, or a required fade margin for availability planning.