What does the Staircase Calculator do?

Calculate risers, treads, pitch and going for a staircase. Checks Building Regulations Part K compliance. All calculations are performed in your browser using official UK rates and thresholds.

Does this include waste allowance?

Yes. Most building material calculations include a standard 10% waste allowance. You can adjust this figure depending on the complexity of your project and cutting requirements.

Material prices are indicative estimates based on average UK prices. Actual costs vary by region, supplier, brand and current market conditions. Always get quotes from local suppliers.

Staircase Calculator

Calculate risers, treads, pitch and going for a staircase. Checks Building Regulations Part K compliance.

Last updated: April 2026 · Source: GOV.UK — Building Regulations Approved Document K

Floor-to-Floor Height (m)

Riser Height (mm)

Regs: 150-220mm

Going Depth (mm)

Regs: 220-300mm

Compliant with Building Regulations (Part K)

Risers

Treads

Pitch

36.6°

Total Going

3.25m

Actual Riser

185.7mm

Stringer Length

4.16m

Building Regs (Part K, England):

Riser: 150-220mm | Going: 220-300mm | Max pitch: 42° | 2R+G: 550-700mm (yours: 621mm)

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

UK Building Regulations (Approved Document K) set strict requirements for domestic staircases. The maximum rise per step is 220 mm and the minimum going (tread depth) is 220 mm. The pitch must not exceed 42°. Additionally, twice the rise plus the going (2R + G) should fall between 550 mm and 700 mm for comfortable use.

This calculator takes the total floor-to-floor height and available horizontal distance, then calculates the number of treads, individual rise, going and overall staircase length. It checks all results against Building Regulations and flags any dimension that falls outside permitted limits.

Headroom must be at least 2.0 m measured vertically from the pitch line. The calculator also shows the stairwell opening length required. For a standard floor-to-floor height of 2.6 m, most staircases need 12–13 risers and a horizontal run of approximately 3.0–3.5 m including a landing.

Example: Floor-to-floor height 2,600 mm, 13 risers

Rise per step: 2,600 ÷ 13 = 200 mm (≤ 220 mm, compliant)
Going per step: 250 mm (≥ 220 mm, compliant)
2R + G check: (2 × 200) + 250 = 650 mm (within 550–700, compliant)
Total horizontal run: 12 × 250 = 3,000 mm (12 treads, 13 risers)
Pitch angle: arctan(200 ÷ 250) = 38.7° (≤ 42°, compliant)

Source: GOV.UK — Building Regulations Approved Document K

Frequently Asked Questions

What does the Staircase Calculator do?: Calculate risers, treads, pitch and going for a staircase. Checks Building Regulations Part K compliance. All calculations are performed in your browser using official UK rates and thresholds.
Does this include waste allowance?: Yes. Most building material calculations include a standard 10% waste allowance. You can adjust this figure depending on the complexity of your project and cutting requirements.
Are prices accurate?: Material prices are indicative estimates based on average UK prices. Actual costs vary by region, supplier, brand and current market conditions. Always get quotes from local suppliers.