I don't know if you've fixed the calculator yet, but I also don't seem to be getting the right values for the acceleration time. In my motor calc thread I had calculated that the robot would have about 3.6m/(s^2) of acceleration which should (according to v=v0 + at) reach the top speed of about 2-3m/s in about 1s or so. Your calculator says it would take 3.47s for 50%.
Also, when I was playing around with values I noticed that the relation between torque (in kg*m) isn't linear with the time required to reach max acceleration, which doesn't make any sense does it? Surely the more torque, the higher the acceleration, regardless?
James