A practical stair layout starts with total rise, then backs into riser count, tread count, total run, and stringer length. Construction Pro's Stair Calculator handles that sequence and also flags common code-check issues when the riser or tread assumptions drift outside typical limits.
This screenshot comes from the main interior stair layout recording for the Stair Calculator.
Builders use this calculation for interior stairs, basement stairs, deck stairs, and remodel work where space gets tight. It is especially helpful when you need to reconcile a target riser with the actual rise available between finished levels.
The examples below reflect the exact sequence used by the Stair Calculator in Construction Pro.
Example 1
Inputs: 108 in total rise, 7.5 in target riser, 10 in tread.
Construction Pro rounds this setup to 15 risers, which means the actual riser height lands around 7.2 in. That produces 14 treads, 140 in of total run, and about 176.8 in of stringer length.
Example 2
Inputs: 120 in total rise, 7.5 in target riser, 10 in tread.
A taller floor-to-floor height pushes this one to 16 risers and 15 treads. The total run becomes 150 in, and the stringer length works out to about 192.1 in. It is a good check before committing to a long straight stair run in a basement.
Example 3
Inputs: 42 in total rise, 7 in riser, 11 in tread.
For an exterior stair with deeper treads, the result is 6 risers, 5 treads, 55 in of total run, and about 69.2 in of stringer length. That makes it easy to compare the stair footprint with the available deck landing space.
Common mistakes
Related guides
Because the total rise has to be split into a whole number of risers. The app rounds the riser count, then shows the actual riser height that fits.
Yes. The Stair Calculator includes total run, stringer length, and the stair angle in the practical layout results.
Use them as a fast screen, then verify your local code requirements before cutting or permitting the stair.
Construction Pro turns total rise into practical stair dimensions and keeps code-check reminders visible while you work.