Best thing to do is head out with your scope and a rangefinder and determine the real distance that x# of md's represents. FWIW, I have this worked out for one of my scopes but it is not mil dot, and there is quite a difference between a young doe and a buck, or between a mule deer and a WT.
Remember that on most scopes these days the reticle is on the second plane, meaning the distance each dot represents is not constant. It will only represent 1 mil when set at a certain magnification. I am sure you understand that but many people do not.