Stair Calculator: UK Part K
Rise, going & pitch checker
Only for iPhone
$2.99 · Designed for iPhone. Not verified for macOS.
iPhone
Design a compliant staircase or check one on site: every result cited against Approved Document K, plus a live pitch check with your phone on the stringer. Works offline.
Design a staircase that passes, or check one that exists - with every result cited against Approved Document K (England).
Stair Calculator is built for UK joiners, carpenters, loft conversion firms, builders and serious DIYers. Enter the total rise - floor to floor, including finishes, and the app reminds you of that classic site mistake - and it works out a compliant flight: riser count, an exactly uniform individual rise, going, pitch and the 2R+G comfort value. Every line carries a pass or fail badge with the exact rule behind it, for example "Pitch 43.1 deg - FAIL - AD K max 42 deg for a private stair".
DESIGN SOLVER
- Height and available run: a fully optimised flight
- Height only: the minimum run a compliant flight needs
- Height with a preferred rise or going: fix one, solve the rest
- Risers divided exactly, never rounded into a flight that no longer sums to your total rise
- When no compliant flight fits, it says so and names the rule that binds
CHECK MODE
Measure an existing staircase - rise, going, pitch, headroom - and get an instant verdict, rule by rule. Made for surveys, condition checks and sizing up a loft conversion before you buy.
LIVE PITCH CHECK
Lay your phone on a stringer, the pitch line, or a straightedge across the nosings and read the pitch live against the 42 deg limit, with clear green, amber and red bands. Calibration offset included for phone cases.
BUILT ON THE RULES, WITH CITATIONS
- Private (dwelling) stairs: rise, going, pitch, 2R+G and uniform-riser checks with paragraph references
- Headroom: the 2000 mm standard, plus the loft conversion relaxation (1900 mm at centre, 1800 mm at the side) handled explicitly
- Landing and riser-count guidance, and a handrail and guarding heights reference
- England, Approved Document K (2013 edition). The app tells you clearly that Scotland and Northern Ireland use their own standards
PRIVATE BY DESIGN
No account, no ads, no tracking, no network use at all. Everything works offline, on site, in a loft with no signal.
A DESIGN AID, NOT AN APPROVAL
Stair Calculator is a calculation aid. It does not replace the judgement of a competent person or a decision by a building control body, and its output is not building regulations approval. Contains public sector information licensed under the Open Government Licence v3.0.
Ratings & Reviews
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The developer, Plan CD, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Rik Watson
- Size
- 2.4 MB
- Category
- Utilities
- Compatibility
Requires iOS 26.0 or later.
- iPhone
Requires iOS 26.0 or later. - Mac
Requires macOS 26.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 26.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 plancd
