Measure first
Measure finished dimensions, actual stock, openings, and site constraints before ordering material.
Stair planning
Stair Calculator: rise, run, risers, and treads
Build a quick stair layout from total rise, total run, and your target maximum riser. Compare the resulting riser height, tread depth, angle, and stringer length before laying out a stringer.
How the estimate works
Use the number as a planning starting point.
Riser count is total rise divided by maximum target riser and rounded up. Tread count is one fewer than riser count; tread depth uses total run divided by treads.
Check the result
Stair geometry affects safety and code compliance. Confirm the governing local requirements, finished-floor conditions, nosing, headroom, landing, stringer stock, and fastening before building.
Plan the next step
Use the related calculators below to turn a first estimate into a material list, layout, or a more detailed project plan.
FAQ
Common Stair Calculator questions
How many treads are in a stair?
For a typical floor-to-floor stair, tread count is often one fewer than riser count because the upper floor serves as the final landing.
Can I use this as a building-code check?
No. It is a planning estimate only; check your current local code and actual site conditions.
Related tools
Keep the project moving.
Deck Stair Calculator
Free deck stair calculator. Estimate deck stair risers, treads, rise, run, angle, and approximate stringer length for early layout planning.
Open Deck Stair CalculatorRise and Run Calculator
Free rise and run calculator. Convert total rise, riser count, and target tread depth into total run, angle, and stringer length estimates.
Open Rise and Run CalculatorStair Angle Calculator
Free stair angle calculator. Convert stair rise and run into degrees, slope percentage, pitch ratio, and approximate stringer length.
Open Stair Angle CalculatorPlanning disclaimer: WoodCutTool results are estimates. Verify measurements, product instructions, material condition, local requirements, and safety practices before buying, cutting, or building.