RF Wireless 4G & 5G

VSWR and Return Loss Calculator

Check antenna and feeder match from one number.

By TheCalcTools Updated Formula checked and tested

Your numbers

Your results

Reflection coefficient |Γ|
Reflection coefficient |Γ|
—
VSWR
—
Return loss (dB)
—
Mismatch loss (dB)
—
Power reflected
—

VSWR and Return Loss Calculator by TheCalcTools

How the VSWR and Return Loss Calculator works

Choose whether you know the VSWR or the return loss and enter the value.

The reflection coefficient is Γ = (VSWR − 1) ÷ (VSWR + 1).

Return loss, mismatch loss and reflected power follow from Γ.

The formula

Γ = (VSWR − 1) ÷ (VSWR + 1)RL = −20 log₁₀ |Γ|

Worked example

Using the default values shown in the calculator:

You knowVSWR
Value1.5
  1. VSWR 1.5 → Γ = 0.5 ÷ 2.5 = 0.2000.
  2. Return loss = 13.98 dB; mismatch loss = 0.177 dB; reflected power = 4.00%.

Result:

Reflection coefficient |Γ|0.2000
VSWR1.500
Return loss (dB)13.98
Mismatch loss (dB)0.177
Power reflected4.00%

Frequently asked questions

What VSWR is acceptable?

Base-station antennas are commonly specified at VSWR 1.5:1 or better (return loss about 14 dB). Above about 1.8:1 deserves investigation.

Can I measure it with a site analyser?

Yes. A cable and antenna analyser (DTF) shows return loss and can locate the fault along the feeder.

Sources and further reading

Feeder and Jumper Loss CalculatorAdd up the losses between the radio and the antenna EIRP and ERP CalculatorHow much power does the antenna effectively radiate? Decibel (dB) CalculatorConvert between ratios and decibels for power and voltage (amplitude) RSRP, RSRQ and RSSI CalculatorRSRQ = N × RSRP ÷ RSSI, in dB SINR CalculatorAdd up interference and noise, then see the SINR Thermal Noise and Receiver Sensitivity CalculatorHow weak a signal can the receiver still decode?

More in RF Wireless 4G & 5G · All calculators

This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.