ToolsProfessional Tool
UK Stair Calculator
Enter your floor-to-floor height and we'll design a compliant staircase to Building Regulations Approved Document Part K, with a comfort score, alternative designs and a sectional drawing.
Approved Document Part K · 2R + G 550–700mm
800mm+ recommended for a main domestic stair
Compare riser counts
This stair complies with Part K geometry rules
Risers
12
216.7mm each
Total run
2750mm
11 goings × 250mm
Pitch
40.9°
max 42°
Comfort
51/100
ideal 2R+G ≈ 630mm
Part K Compliance Checks
Riser 216.7mm — allowed 150–220mm
Going 250.0mm — allowed 220–300mm
2 × Rise + Going = 683mm — must be 550–700mm
Pitch 40.9° — max 42°
Stair width 860mm — 800mm+ recommended for a main domestic stair (no statutory minimum for private stairs)
Headroom: min 2000mm measured vertically above the pitch line
Landing: min 860mm clear (equal to stair width) top and bottom, level and clear of door swings
Handrail: 900–1000mm above pitch line; one side if stair <1m wide, both sides if wider
Guarding: required where drop exceeds 600mm; 100mm sphere must not pass through
Max 36 risers in consecutive flights without a change of direction (general access)
Guidance tool only. Always confirm your design with Building Control or a qualified professional. Need a full staircase design? Get in touch.
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