VSWR & Return Loss Calculator
Convert between VSWR, return loss, reflection coefficient, and mismatch loss. See reflected vs transmitted power.
Inputs
Results
Return Loss
13.98 dB
Reflection Coefficient (Γ)
0.2
Power Transmitted
96 %
How to Use This Calculator
- Enter the measured VSWR from your antenna analyzer (ideal = 1.0:1, acceptable <2.0:1).
- Set transmitter input power (W).
- Review return loss (dB), reflection coefficient, mismatch loss (dB), and reflected power percentage.
- VSWR above 2.0:1 reflects >11% power and may damage your transmitter -- investigate antenna connection.
- Use mismatch loss to quantify efficiency reduction from antenna impedance mismatch.
How the result changes with VSWR
| VSWR | Return Loss | Reflection Coefficient (Γ) | Power Transmitted |
|---|---|---|---|
| 5.9 | 2.97 dB | 0.7101 | 49.57 % |
| 18 | 0.97 dB | 0.8947 | 19.94 % |
| 33 | 0.53 dB | 0.9412 | 11.42 % |
| 45 | 0.39 dB | 0.9565 | 8.51 % |
What each input means
- VSWR
- Voltage Standing Wave Ratio (1.0 = perfect match, higher = worse)
- Input Power
- Transmitter power to calculate reflected/transmitted wattage
How this is calculated
Formula
Γ = (VSWR - 1) / (VSWR + 1); RL = -20·log₁₀(Γ)Worked example, using the default values
- Identify Input ParametersVSWR = 1.5, Input Power = 100 = 2 input(s) provided
- Calculate Return LossReturn Loss = rl13.98 = 13.98
- Calculate Reflection CoefficientReflection Coefficient0.2 = 0.2
- Calculate Power TransmittedPower Transmitted96 = 96
- Calculate Mismatch LossMismatch Loss0.177 = 0.177
- Calculate Power ReflectedPower Reflected4 = 4
Engine last updated . Checked against 4 independently-derived tests — how we verify calculators.
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