I couldn't get into my attic without a ladder, so I built myself one.
I used 2-2x4s for the sides, and 1x3 strapping for the rungs.
I used 4 long brass screws per step.
I layed the 2x4s down with the 2 inch side facing me and estimated the distance between the two. I figured out the length of the rung and cut them out all at the same time.
I also estimated the distance for the first and second step. I started at the bottom.
"I probably could have gone to a ladder in the supply store and took measurements while I was there but I didn't think of it at the time."