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Stairs for an 8-foot Ceiling

A code-compliant straight staircase to an 8-foot ceiling takes 15 equal steps. Here is the exact riser, tread run, pitch and floor opening — already calculated, ready to adjust.

The 8-foot ceiling staircase at a glance

A finished 8-foot ceiling is not the same as the height your stair has to climb. Between the ceiling below and the finished floor above sit the joists, subfloor and floor covering — about 12" in a typical timber floor — so the real floor-to-floor rise is 9'. Running that rise through the stairs calculator under the US IRC gives the code-compliant straight flight below. Every figure is computed, not rounded by hand.

Dimension	Value
Total rise (floor to floor)	9'
Number of steps (risers)	15
Number of treads	14
Riser height (each step)	7 3/16"
Tread run / going	11"
Total run (horizontal length)	12' 9 3/4"
Stair angle / pitch	33.2°
Stringer length	15' 7 15/16"
Floor opening needed	10' 11"

Computed for a straight flight with a 11" going and a 6' 8" headroom target under IRC 2021. Switch the unit toggle in the header to read every value in metric or imperial.

Open this stair in the calculator Tweak the 15-step 8-foot ceiling stair live — 3D diagram + code check

How it fits your space

An 8-foot ceiling stair built straight needs a clear floor length of about 12' 9 3/4" from the bottom step to the top nosing — that is the total run, the footprint the flight occupies on the lower floor. You also have to cut a hole in the floor above: the floor opening has to be at least 10' 11" long for someone to walk up without ducking, keeping the 6' 8" of headroom the code wants above every nosing.

At 7 3/16" per riser and a 11" going, the pitch lands at 33.2° — a very comfortable stair to climb. If your run is tight, an L-shaped or stairs with a landing layout folds the same 15 steps into a shorter footprint; if it is really tight, a spiral staircase climbs the same rise in a small circle.

Does it meet code?

Run against IRC 2021, the computed 8-foot ceiling stair passes the dimensional rules. The same checks run live in the calculator the moment you change a number.

Riser height · IRC R311.7.5.1 Riser 7 3/16" is within the IRC 2021 maximum of 7 11/16".
Tread run (going) · IRC R311.7.5.2 Run 11" meets the IRC 2021 minimum of 10".
Headroom · IRC R311.7.2 Provide at least 6' 8" of headroom above the nosing line. Minimum floor opening: 10' 11".
Stair width · IRC R311.7.1 Width 36" meets the IRC 2021 minimum of 36".
Handrail · IRC R311.7.8 A handrail is required (4+ risers), mounted 34"–38" above the nosings.
Guard · IRC R312.1 The total drop exceeds 2' 6", so a guard at least 36" high is required, with balusters that reject a 4 3/8" sphere.
Rise between landings · IRC R311.7.3 The flight rises 9', within the 12' 7" allowed between landings.
Riser uniformity · IRC R311.7.5.1 All 15 risers are equal, within the 3/8" uniformity rule.

Common pitfalls for a 8-foot ceiling stair

Measuring to the ceiling, not the floor above. The stair climbs floor to floor — 9' here — not the 8' ceiling height. Forget the 12" floor structure and you end up one short step at the top.
Uneven top or bottom step. All 15 risers must be equal. Measure the finished floor-to-floor rise (after flooring is down) and divide by the step count so the last riser matches the rest.
Forgetting the floor opening. The hole above has to be roughly 10' 11" long or tall walkers clip their heads near the top. Size it from the headroom, not by eye.
Skimping on the run. Dropping the going below 10" to save floor space fails the IRC tread-depth rule and makes the stair feel steep. Turn the flight instead of shrinking the treads.

Stairs for other ceiling heights

Stairs for a 9-foot ceiling 17 steps Stairs for a 10-foot ceiling 19 steps Stairs for an 11-foot ceiling 21 steps Stairs for a 12-foot ceiling 22 steps Stairs for a 2.4 m ceiling 15 steps Stairs for a 2.7 m ceiling 17 steps Stairs for a 3 m ceiling 19 steps

Calculators for your 8-foot ceiling stair

Stairs Calculator Enter one measurement — your total rise — and get a complete, code‑compliant stair layout with a 3D diagram, stringer cut list, and printable template. Free, instant, in inches or millimeters. Stair Rise and Run Calculator Turn one total‑rise measurement into equal risers and runs that meet code — with the comfort rules (2R+T and Rise+Run) checked for you. Stair Stringer Calculator Get the exact stringer length, throat depth, recommended board size, and a step‑by‑step cut layout with framing‑square settings — then print a full‑scale template. Stairwell Opening Calculator Find the minimum floor-opening length your stairwell needs for code headroom — from your rise, run and floor thickness — with a 2D section showing the clearance line and a live code check.

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

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.