Stairs with Landing Calculator
Break a tall staircase into two safe flights with a landing — Stairs Calc splits the rise, sizes each flight, and checks the maximum rise between landings.
Two parallel flights with a 180° half-landing (switchback).
Finished floor to finished floor — split across the flights.
The depth you step on, not counting the nosing.
Top of the rail above the nosing line. Applied to every flight.
How the handrail turns at the landing — square corners (straight) or a smooth wreath (curved). Shows in the 3D model.
The turn landing — at least as deep as the stair is wide.
The open slot between the two flights. Set 0 for a tight dog-leg (flights touching); open it up for an open-well switchback.
Move the landing up or down the flight — the plan and 3D model follow. The landing doesn't have to sit in the middle.
Flight 1
Steps (risers)
16
15 treads
Riser height
7"
177 mm
This flight's rise
9' 3 3/4"
2.839 m
Tread run
11"
279 mm
Total run
13' 8 3/4"
4.185 m
Stringer length
16' 7 1/16"
5.057 m
Flight 2
Steps (risers)
15
14 treads
Riser height
7"
177 mm
This flight's rise
8' 8 3/4"
2.661 m
Tread run
11"
279 mm
Total run
12' 9 3/4"
3.906 m
Stringer length
15' 6 1/16"
4.726 m
Landing & footprint
Landing depth
3'
914 mm
Turn
180°
switchback
Footprint length
16' 8 3/4"
5.099 m
Footprint width
6' 10 3/4"
2.102 m
When you need a landing
A tall flight has to be broken by an intermediate landing. Enter your total rise and the calculator’s Code panel flags it the moment you exceed the limit between landings — 12′-7″ under the IRC and 12 ft under the IBC. You also need a landing wherever a door swings over the stairs and at the top and bottom of most flights. Split your rise into two flights with a landing between them and size each flight separately. Where even a landing won’t fit, a spiral staircase calculator climbs the same rise in a far smaller footprint.
Landing size requirements
A landing must be at least as deep as the stair is wide, and never less than 36″ in the direction of travel. A straight-run landing can also change direction — turn 90° for an L-shape or 180° for a U-shape — which lets a long flight fit a shorter footprint. If you’re turning the stairs, use the L-shaped & U-shaped calculator to lay out the turn and any winder treads.
Frequently asked questions
When do stairs need a landing?
A landing is required when the vertical rise of a single flight would exceed the code limit — 12′‑7″ in the IRC and 12 ft in the IBC — and wherever a door swings over the stairs. Stairs Calc tells you when your flight crosses that limit.
How big does a stair landing have to be?
A landing must be at least as deep as the stair is wide, and no less than 36″ in the direction of travel. Stairs Calc checks your landing depth against the stair width.
Can a landing change direction (L‑shaped)?
Yes — a landing can turn the flight 90° (an L) or 180° (a U). To lay out the turn geometry and winder treads, use the L‑shaped & U‑shaped staircase calculator.
What's the max number of steps without a landing?
It depends on the rise limit, not a fixed step count: a flight may climb up to 12′‑7″ (IRC) between landings, which at a 7¾″ maximum riser is about 19 risers. Stairs Calc splits taller staircases into compliant flights automatically.
Related stair calculators
Written by the Stairs Calc editorial team. Methodology and code references: see our methodology.
Built and maintained by builders, drafters and engineers who plan stairs for a living — every code limit is transcribed from the published standard and cited to its exact section.
Last reviewed 2026-06-20 against IRC 2021/2024
Stairs Calc gives accurate geometry and checks it against published building-code limits, but results are estimates for planning. Codes are adopted and amended locally and change over time. Always confirm dimensions against your local adopted code and a licensed professional before you build.