stairstringers

Stair stringer calculator

For feedback or support please contact me at framingcalc@gmail.com. If you like the app please leave a review / rating.

Input values

Enter values in decimal or imperial format, an apostrophe suffix denotes feet. Examples of valid inputs:

Input fields

RO rise - the total rise of the stairs, can be used to find landing height

Rise - rise of one step

Max rise - maximum rise of each step

No. of treads - total number of treads in the stair

Run - the run of one step

Flooring tk - thickness of flooring to be installed after stringers

Tread tk - thickness of finished treads

Output results

Top riser - The distance from top of stair hole to top of stringer (forms the last riser of the stairs)

Risers - total number of risers in stairs including riser formed by top of stair hole

Stringer length - The total length of board you need to cut the stringer from

Marks - Each mark corresponds to a point of a step on the stringer with the last mark being the end of the stringer. Mark the lengths along the edge of a board. Place your angle guide (framing square etc.) on these points to mark the steps.

How it is calculated

Stairs are calculated from finished floor to finished floor using the given flooring thicknesses. The rise (if not given) is calculated from (RO rise - btm flooring tk + top flooring tk) / Max rise. The bottom rise is adjusted to account for tread thickness and flooring thickness.

Notes

If you use the rise to calculate your stairs there will be a remainder due to rounding to account for. This is shown as (REM: ) next to the rise value. For example a REM of -1/2 means you need add 1/2 to the rises over the length of the stringer. You do not need to do this if using the generated marks.