Bubbles in the tranny oil

I checked my tranny oil and I know have bubbles in it (while it is running). I'm guessing that that's bad. I'm going to change the oil in it tonight and when my gasket and filter get in then I'll drop the pan and change it again. Does anyone with a transmission dipstick that actually works know how much oil you put in it after a regular drain? I know some remains in the torque converter. My dipstick is retarted and who knows how much is already in it, although I guess too much right now