Staircase Size Calculator
Enter the floor-to-floor height, the thickness of the upper floor, the stair width and the layout. The calculator gives the footprint, the length of stairwell opening for 2 m headroom and the stringer length.
- Straight, L or U layout
- Stairwell opening
- Stringer length
Uses 250 mm goings and risers of 200 mm or less. Floor thickness includes joists, boards and ceiling.
The staircase footprint decides how much room you lose on both floors. A straight stair is simple but long. Turning it with a quarter landing makes an L shape that fits into a corner; a half landing makes a U that is short but wide. The opening above must be long enough to keep 2 m of headroom.
Staircase footprint chart
860 mm wide, 250 mm goings. Search for a floor height.
| Floor to floor (mm) | Risers | Straight | L shape | U shape |
|---|---|---|---|---|
| 2400 | 12 | 2.75 × 0.86 | 2.36 × 2.11 | 2.36 × 1.82 |
| 2600 | 13 | 3.00 × 0.86 | 2.36 × 2.36 | 2.36 × 1.82 |
| 2800 | 14 | 3.25 × 0.86 | 2.61 × 2.36 | 2.61 × 1.82 |
| 3000 | 15 | 3.50 × 0.86 | 2.61 × 2.61 | 2.61 × 1.82 |
Footprints include the landing. A U-shape leaves a 100 mm gap between flights for the handrail.
Floor height and footprint
Straight, L and U layouts. Slide the floor-to-floor height.
The drawing shows a straight flight in plan. Each line is the front edge of a tread.
How to plan a staircase
From the floors. Step through it.
Measure floor to floor
Finished levels.
Stringers are the boards either side that carry the treads. Buy them about 300 mm longer than the sloping length.
Straight, L or U
Staircase layouts. Compare them.
Cheapest and simplest, needs a long wall.
Turns 90° at a landing. Fits a corner.
Doubles back. Short but wide.
Winders, triangular steps in a turn, save more space than a landing but are harder to use.
Before ordering a staircase
Measure carefully. Tick each item.
Tick each item as you go.
Most stair makers want the floor-to-floor height to the nearest millimetre, measured in several places.
What you get
Staircase plan. Each tile explains one result.
Floor area used.
Risers and goings.
For headroom.
Length to buy.
Angle.
The opening length assumes the stair rises towards the opening edge. Headroom is measured vertically from the pitch line.
Frequently Asked Questions
No question matches that search.
How much space does a staircase need?
A straight stair for a 2.6 m floor height needs about 3 m × 0.9 m.
How big should the stairwell opening be?
Long enough for 2 m headroom, often 2.5 to 3 m for a straight stair.
How wide should a staircase be?
800 to 900 mm is common in homes; 1 m or more feels generous.
Does an L-shaped staircase save space?
It saves length but needs more width. It fits well in a corner.
How long should stringers be?
The sloping length plus about 300 mm.
What is a quarter landing?
A square landing where the stair turns 90°.
How deep should a landing be?
At least as deep as the stair is wide.
A staircase that fits
Count the steps, choose the layout that suits the room and check the opening above. You will know exactly how much space the stair takes on both floors.
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