what are the correct units to use in each of the variables in the adiabatic compressible flow equation for the gas pressure drop?

the equation is here:

http://www.pipeflowcalculations.com/pip ... l-flow.php

this is the result i received from the calculator:

I am trying to calculate the flow in liters/min of CO2 through a pipe with D=.114 in and L=3.5 in, p1=760 mmHg, p2= 20mmHg. I used the gas pressure drop calculator, but I want to check my work by hand because as the pressure difference increases, the flow rate decreases (when P1-P2 is larger than about 290 mmHg). Am I using the right equation to do so? if so, what units should i be using with each of the variables?