The reflection coefficient is the ratio of reflected wave to incident wave at point of reflection. This value varies from -1 (for short load) to +1 (for open load), and becomes 0 for matched impedance load.
Formala is:

where ZS is the impedance toward the source,
      ZL is the impedance toward the load.

reflection coefficient(Γ)=
[dB]
return loss =

return loss Calculator:(by using VSWR)

Formula is::

VSWR=
return loss =

This is the ratio of maximum voltage to minimum voltage in standing wave pattern.
It varies from 1 to (plus) infinity.
Formula is::

reflection coefficient(Γ)=
VSWR =

return loss(RL)=
VSWR =