I think you're better off figuring it long hand. Divide it out so it does meet code. And then draw it into, if needed, your cad program. It's pretty easy to figure... height divided by 7.25" gives you number of risers.. most likely will have a fractional number. Bump number up or down and divide that back into height to give you height of risers. Use code in your area to figure out what length tread is and figure if you have enough space.
That's pretty cut and dry - there are many other variables that need to be considered. Use of stair, users of the stair, other structural issues, surroundings, materials, etc. But that's the basics.