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Trade toolkit · Carpentry

Stair Calculator: Rise, Going and Pitch to UK Building Regulations

Enter the floor to floor height and the calculator works out the number of risers, the rise and going of each step and the pitch, checked against Approved Document K for private, utility and general access stairs. Every legal option is listed, with the best one drawn to scale.

Use the calculator
Side view of the recommended flight, drawn to scale.

Every option that works

Each row is a different number of risers. Rows that break a rule are greyed out.

RisersTreadsRiseGoingTotal goingPitch2R+GChecks

Based on Approved Document K (England). Wales and Scotland have their own rules. Check with building control before you build.

How to use it

From floor to floor height to a legal stair.

  1. Measure the total rise. From finished floor downstairs to finished floor upstairs. Allow for the flooring and any screed still to go down.
  2. Choose the type of stair. Private is a stair inside a single home. Utility and general access have tighter rules.
  3. Add the space for the going, if it is tight. If you have a fixed length to fit the flight into, enter it. Leave it blank to see the ideal going for each number of risers.
  4. Pick from the options. The recommended option sits closest to a comfortable 2R + G of around 625 mm with a pitch of around 37°. Rows that break a rule are greyed out.

The rules for a private stair

  • Each rise between 150 and 220 mm.
  • Each going between 220 and 300 mm.
  • Pitch no steeper than 42°.
  • Twice the rise plus the going (2R + G) between 550 and 700 mm.
  • All rises and goings in a flight the same.
  • At least 2 m clear headroom over the pitch line, or 1.9 m in the middle of a loft conversion stair.

Questions

Common questions.

How many steps for a 2.6 m floor to floor height?

For 2600 mm, 14 risers of 185.7 mm suits a private stair well, with a going of around 250 mm and a pitch of around 36°. Enter your exact height to see every legal option.

What is 2R + G?

Twice the rise plus the going. It describes how comfortable a step is to walk. Building Regulations require it to be between 550 and 700 mm, and most people find around 600 to 640 mm comfortable.

Can a private stair have open risers?

Yes, but the treads should overlap by at least 16 mm, and the gaps should not let a 100 mm sphere pass through, so that small children cannot climb or fall through.

Is this the same in Scotland and Wales?

No. This tool follows Approved Document K for England. Wales has its own Approved Document K, and Scotland uses the Building Standards Technical Handbook, which sets different limits. Always check with your building control body.

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Joinery job on?

Panels cut and edged for the job.

Send us your cutting list for spandrel panels, cupboards under the stairs and fitted storage. Email info@dtjinteriors.co.uk, call 0115 784 8231 or WhatsApp 07956 032306.

Contact us
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DTJ Interiors Ltd
Unit 5 Atlas Mills, Birchwood Avenue
Long Eaton, NG10 3ND

0115 784 8231
info@dtjinteriors.co.uk
WhatsApp 07956 032306

Workshop and collection
Monday to Friday, 8am to 4:30pm

Delivery across the East Midlands for £99 + VAT, and further afield priced per job.

DTJ Interiors Limited · Company no. 15242186 · VAT GB460641310
Registered office: The Mills, Canal Street, Derby DE1 2RJ

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