Stair Stringer Calculator
Risers = ceil(total rise / target riser); treads = risers − 1.
Inputs and units
- Total vertical rise: Enter your value in the format and unit shown.
- Target maximum riser: Enter your value in the format and unit shown.
- Tread going: Enter your value in the format and unit shown.
- Dimension unit: Choose Metres, Centimetres, Millimetres, Feet, Inches.
Calculation method
Risers = ceil(total rise / target riser); treads = risers − 1.
Worked example
The example values are: Total vertical rise = 2.8; Target maximum riser = 0.18; Tread going = 0.28; Dimension unit = m
- Risers: 16
- Treads (top floor is final landing): 15
- Actual rise per step (m): 0.175
- Total run (m): 4.2
- Rise/run diagonal (m): 5.0477717857
Assumptions and limitations
All dimensions use the chosen unit. Diagonal is a geometry estimate, not a finished cut list; nosing, landings, headroom and local requirements need separate checks.
Using your result
Select Calculate after changing inputs. Copy result copies the displayed output; Download result saves a text file. Reset returns the form to its example inputs. Calculations run in your browser.
Stair Stringer Calculator FAQs
What method does this calculator use?
Risers = ceil(total rise / target riser); treads = risers − 1.
What should I check before using the result?
All dimensions use the chosen unit. Diagonal is a geometry estimate, not a finished cut list; nosing, landings, headroom and local requirements need separate checks.