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Straight stair calculator with live plans

Enter the finished floor-to-floor height and the horizontal space available for the flight. StairEditor proposes a step count, then updates the side, top, and isometric views while you refine the design.

Open this calculator

Free, no sign-up required.

Best for

  • Open rooms with enough continuous run
  • Basement and loft access
  • Checking an existing straight-flight proposal

Measurements to take

  • Finished floor-to-floor height
  • Maximum horizontal flight length
  • Flight width
  • Stairwell opening and floor thickness

Results you get

  • Suggested number of steps
  • Riser height and going
  • Pitch and Blondel value
  • Estimated minimum headroom
  • Live 2D, isometric, and parts views

What to have reviewed

Straight stairs receive the most detailed PDF currently available in StairEditor, including individual tread information. Confirm structure, joinery, local rules, and site measurements with a qualified professional before cutting material.

Common questions

What measurements do I need?

Start with finished floor-to-floor height and the maximum horizontal run. Stair width and opening dimensions improve the headroom review.

Does the calculator choose the step count?

Yes. Auto mode proposes a step count from the geometry and Blondel target. You can switch to a manual count to compare alternatives.

Test my measurements