for machine, always go actual. The weights on machines is generally a bit misleading, because they are on a track. For example, doing a barbell bench press, I can typically push 235-240 pounds, but on a machine, I can basically add 100 to it and do around 350. The same for flies, where I will do a dumbbell fly for 40 pounds, but on a pec deck machine, i will top it out at 300 and it still feels light.