Percent Reflected Power to VSWR

This tool gives the VSWR from the percent reflected power.

Enter the % reverse power and both the reflection coefficient (Γ) and Voltage Standing Wave Ratio (VSWR or SWR) will be calculated.

Formula

Γ = √(Reverse Power_%/100)

VSWR = (1+|Γ|)/(1-|Γ|)

If the reverse power is 5%, the VSWR is 1.58. Slightly higher than a target value of 1.5 (considered a good value).

If 50% of the power is reflected, the VSWR is 5.82. That represents a poor match.

If all the power is reflected, Γ = 1, the VSWR is ∞ – the poorest possible match.