Most projects begin with a single measurement
Enter your total floor-to-floor rise and everything else in this category follows from it.
Stair Rise and Run Calculator
The full planner — enter your total rise and get riser height, tread depth, step count, stair angle and stringer length in one pass.
The rest of the geometry cluster
Single-answer tools for one specific measurement, plus a comparison tool that runs three comfort formulas at once.
Stair Stringer Calculator
Turns a finished design into notch points, mounting type, a cut list, and a printable PDF/SVG diagram — ready to cut.
Number of Steps Calculator
A quick single-answer tool: enter your total rise, get the number of steps.
Stair Angle / Pitch Calculator
Stair angle in degrees from rise and run, with comfort-range warnings if it's too steep or too shallow.
Riser Height Calculator
Exact, code-uniform riser height across the full flight of stairs.
Tread Depth Calculator
Minimum and comfortable tread depth for a given riser height.
Stair Headroom Calculator
Clearance from the nosing line to the ceiling above, checked against IRC/IBC minimums.
Stair Nosing Calculator
Nosing overhang length and effective tread depth once the nosing is factored in.
Stair Width Calculator
Minimum clear stair width for residential vs. commercial stairs.
Stair Comfort Formula Calculator
Runs the 7-11 rule, the 2R+T rule, and the Blondel formula against the same inputs, side by side.
Common questions about stair geometry
Which calculator should I start with?
What's the difference between the Rise and Run Calculator and the Stringer Calculator?
Do these calculators check code compliance?
Do these support metric units?
Browse the other 9 categories
Once your geometry is locked in, these are the natural next stops — structural sizing, material take-offs, railing, code checks and cost.