The preliminary layout uses 16 risers, 15 treads and a 4.05 m horizontal run.
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Stair Calculator
Start with the total rise and preferred step dimensions to produce a practical preliminary stair layout.
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Stair dimensions details
Formula & disclaimer
Risers = Ceiling(Total Rise Γ· Preferred Riser); Actual Riser = Total Rise Γ· Risers; Run = Treads Γ Tread Depth
View assumptionsFormula reviewCalcs at Hand Editorial TeamVerified 31 August 2026 Β· automated checks included
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How to read this result
Three useful checks, kept deliberately short.
A 280 cm rise with an 18 cm preferred riser and 27 cm tread: Round the riser count up Β· Recalculate the actual riser height Β· Multiply tread count by tread depth.
Building codes, headroom, landings, handrails and structural design are not assessed by this dimensional estimate.
Formula and assumptions
Risers = Ceiling(Total Rise Γ· Preferred Riser); Actual Riser = Total Rise Γ· Risers; Run = Treads Γ Tread DepthA straight stair normally has one fewer tread than risers when the upper floor acts as the final landing.
Keep in mind: Use this for preliminary measurement only. A qualified designer or contractor must verify structure and local code compliance.
Produced byCalcs at Hand Editorial Team
Last formula check31 August 2026
Review methodKnown examples + boundary cases
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