It's not just based on the stepper motors, but the mechanical properties of the machine, and the operating voltage and current you're driving the motors with.
There is no hard and fast way to work this out purely with math, because there are a huge number of unknowns in the mechanical system.
eg: Do you know how much friction the bearings/bushings on your axes require you to overcome? What sort of drive mechanism are you using? If there's belts involved, which tooth type are you using, how much tension have you got in the belts. How good are the bearings in your motors? And that's just what I can come up with in my head without stopping to think about it.
There is no hard and fast way to work this out purely with math, because there are a huge number of unknowns in the mechanical system.
eg: Do you know how much friction the bearings/bushings on your axes require you to overcome? What sort of drive mechanism are you using? If there's belts involved, which tooth type are you using, how much tension have you got in the belts. How good are the bearings in your motors? And that's just what I can come up with in my head without stopping to think about it.