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Staircase Material Calculator — Treads, Risers & Stringers
Calculate the materials list for building a staircase. Get quantities for treads, risers, stringers, newel posts and handrail.
Total vertical rise
Horizontal depth of each tread (min 220mm Part K)
Width between strings
0 = straight flight. Any winders add a turn newel; stringer/handrail figures still assume a straight flight — use the Winder Staircase Calculator for turned-stair geometry
Default: 22mm
Default: 9mm
Default: 250mm
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How We Calculate This
This calculator determines the number of risers from your floor-to-floor height, then calculates all timber materials needed including treads, risers, stringers and fittings.
Formulas
- Number of risers = Total rise ÷ Target riser height (~190mm)
- Number of treads = Risers − 1 (winder treads replace straight treads within the same flight — they are not added on top)
- Stringer length = √(Total rise² + Total going²)
The stringer and handrail lengths assume a straight flight. For quarter-turn or half-turn (winder) stairs the geometry splits into two flights at 90°, so use our Winder Staircase Calculator for accurate winder tread dimensions and string lengths.
Frequently Asked Questions
The number of treads is typically one less than the number of risers for a straight staircase. For a standard UK storey height of 2600mm with 190mm risers, you need approximately 13-14 risers and 12-13 treads. Use our Staircase Calculator to work out the exact riser height, going and number of steps.
Stringers are typically cut from 250mm or 300mm wide boards, usually 38-50mm thick softwood. The length is calculated as the hypotenuse of the total rise and total going.
Winders are triangular treads used to create a turn in the staircase instead of a landing. They are commonly used for quarter-turn and half-turn stairs to save space. Use our Winder Staircase Calculator for detailed winder tread dimensions and compliance checks.
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Last updated: March 2026
Verified against UK standards · estimates only, confirm with your supplier.