Stair Calculator

Stair Calculator Instructions

Enter the total rise. You can use feet, inches, and fraction (11′ 10 3/4″), inches and fraction (142 3/4″), or decimal values (142.75). Know that the rise should be measured from where the stairs will end. Any fall in the ground must be compensated for. Use the number of steps to find out where the steps will end. Always multiply this by 10″ to get the run.

Since you are possibly dealing with a slope in the ground, the easiest way to find out where the stringer will end is with a sting and a framing square. Use the guesstimated rise along with a ten inch run on a framing square at the top of the rise. Stretch the string so that the it aligns with 10″ for the run and the calculated value for the run. Test this, adjust it, and re-test it. You want the deck stairs to be accurate. If you are dealing with landings, then click here.

Never exceed one inch for the back cut  on a stringer.

Note the back cuts on these deck stair stringers do not exceed 1″.