Why calculate steps/unit? Just try it...

Soapbox mode on:

If you are building a machine and calculating ratios it makes a lot
of sense to figure steps per inch but if you are trying to run an
existing rig it just seems easier to plug a number and try it. Jog in
one direction to take up backlash, install an indicator behind the
direction of move at near max travel and do a .25" jog. The
percentage difference between what you asked for and what you got can
be used to modify the steps per unit. You can also just read the hand
wheel. It seems like a silly intelectual exercise and waste of time
to try to pre calculate it. Your likely to be wrong anyway.

Soapbox mode off.

Roger S