find the $v/c$ ratio

for particle's energy, in the unit of MeV/A

$\gamma \approx$

$v/c \approx$ = %

Note: CATKIN also provides this calculation:

Q-value calculator

LISE++, CATKIN, and NNDC online calculator are all very helpful to do the Q-value calculations. And I found the easiest one is the NNDC online calculator (link), meanwhile check the "Help", inside it there are pretty well written documentations.

For example, we want to calculate the Q-value for the reaction of $^{124}$Xe(d,p)$^{125}$Xe.