A steel stair takeoff breaks each flight into stringers, treads, risers, landings, posts, and rail, then prices rail separately by linear foot. Fabricated steel stairs typically run $1,500–$4,500 per flight for standard commercial pans, or $150–$400 per riser; handrail and guardrail run roughly $60–$180 per LF fabricated and installed, depending on finish and infill.
Stairs and rail are where structural estimators lose money, because the tonnage is trivial and the labor is everything. A flight of stairs might weigh 800 lbs and carry 40 hours of fab time. Price it per ton like beams and you'll win every stair job in town — once each.
What are the parts of a steel stair takeoff?
Break every stair into the same checklist, every time:
| Component | Typical material | How to count |
|---|---|---|
| Stringers | C12x20.7, MC12x10.6, or 1/2" plate | 2 per flight (3 if over ~5'-0" wide), length = slope run |
| Treads | Concrete-filled pan (14 ga), bar grating, or checker plate | Risers per flight minus 1, plus landing nosings |
| Risers | Closed (pan) or open | Count = floor-to-floor height ÷ riser height (max 7" IBC commercial) |
| Landings | Checker plate or pan on channel/angle frame | Per plan; frame + infill + headers |
| Posts | HSS2x2 to HSS3x3, or 1-1/2" pipe | At landings, turns, and every 4'-6' of open rail |
| Guardrail | 1-1/2" pipe or HSS top rail + infill | LF along open edges, 42" high |
| Handrail | 1-1/2" round pipe or tube | LF along both walls/sides of every flight |
| Misc | Closure plates, kick plates, clip angles, embeds | The stuff that never makes the drawing but always makes the shop ticket |
C12x20.7 is the default stringer on commercial pan stairs; MC12x10.6 shows up where the architect wants a slimmer profile, and plate stringers where they want it slimmer still (and your fab hours want a raise). A quick refresher on channel vs MC designations is in our steel member types guide.
How do I count treads, and what kind are they?
Risers first: floor-to-floor height divided by riser height gives risers per flight; treads are risers minus one. A 12'-0" floor-to-floor at 7" risers is 21 risers, so 20 treads across (usually) two flights with an intermediate landing.
Tread type swings cost more than anything else on the stair:
- Concrete-filled pans — the commercial default. Cheap steel (14-gauge formed pan), but somebody has to fill them; confirm whether concrete fill is your scope or the GC's.
- Bar grating treads — industrial standard, bought as catalog items with nosings. Fast takeoff: count and size. The National Association of Architectural Metal Manufacturers publishes the standard grating tread references at naamm.org.
- Checker plate (diamond plate) — 1/4" is typical; heavier fab than grating because the shop cuts and welds each tread.
- Precast or wood-filled — you supply the pan or frame only; exclude the fill explicitly.
Landings are miniature floors: takeoff the frame (channels or angles), the infill plate or pan, the concrete fill question again, and the header connections to the structure or to posts.
How do I take off handrail vs guardrail?
They're different line items with different rules, and mixing them is the most common railing takeoff error:
- Guardrail protects an open edge — 42 inches high with infill (pickets at 4" max clear, mesh, or panels). Measure LF along every open edge: stair open sides, landing edges, mezzanine perimeters, ramp edges. OSHA's walking-working surfaces rule (29 CFR 1910.28–29) drives the industrial version; see osha.gov for the current text.
- Handrail is the graspable rail at 34–38 inches — required on both sides of most commercial stairs. It's either wall-mounted (brackets every 4'-0" or so) or mounted on top of / beside the guardrail.
So one open-sided stair flight generates BOTH a guardrail LF and a handrail LF on the open side, plus a wall rail on the closed side. Estimators who take off "railing" as one number routinely miss a third of the linear feet. Count posts separately — post count drives welding and base plate hours more than rail LF does, and welding cost is most of a railing's price.
Should I price stairs per flight or do a detailed takeoff?
Both, in sequence. Per-unit numbers are for sanity checks and budget quotes; detailed takeoff is for real bids. Editorial ranges for typical US commercial work in 2026:
| Item | Budget range | Notes |
|---|---|---|
| Standard pan stair, per flight | $1,500–$4,500 fabricated | 3'-8" to 4'-0" wide, C-channel stringers, ~10 risers |
| Same, per riser | $150–$400 | Scales better across odd flight heights |
| Industrial grating stair, per flight | $2,000–$5,000 | Grating treads, often galvanized |
| Steel pipe guardrail | $60–$140 per LF | Painted, picket or 3-rail infill |
| Handrail, wall-mounted | $40–$90 per LF | Brackets and returns included |
| Ornamental/architectural rail | $150–$400+ per LF | Glass, cable, or stainless — different universe |
| Landings | $30–$60 per sq ft | Frame plus checker plate, no fill |
Add 25–50% to fab pricing for galvanizing and handling on exterior stairs, and treat monumental or architecturally exposed stairs as custom work — the ranges above don't apply. When your detailed takeoff lands outside these ranges, one of the two is wrong; find out which before bid day. For overall market pricing context, see steel fabrication costs in 2026.
What code-driven items do estimators miss?
The steel is easy to see. The code geometry is not, and it's all fabricated metal that someone must pay for:
- Handrail extensions. IBC and ADA require the handrail to extend 12 inches horizontally beyond the top riser and one tread depth plus 12 inches at the bottom (jurisdictions vary). That's 2–4 extra LF plus bends per rail, per flight — on a 6-story stair tower with rail both sides, roughly 30–50 LF of rail that isn't on the plan dimension strings.
- Returns to wall. Handrail ends must return to the wall or post, not stick out. Each return is a bend or a welded elbow — count fittings, not just LF.
- Continuity at landings. The inside handrail should run continuous around switchback landings; that inside rail is longer than the flight geometry suggests and full of bends.
- Picket spacing. The 4-inch sphere rule sets picket count. Infill at 4" on center versus 6" is a 50% jump in picket welding.
- Kick plates / toe boards. 4-inch minimum at industrial guardrail where things can fall on people below (OSHA 1910.29). Cheap steel, real hours.
- Closure and trim. Stringer closure plates, drywall angle, nosing at the top landing — the "misc" that turns 800 lbs of stair into 1,100 lbs of shipped steel.
A useful discipline: after the takeoff, walk the stair mentally from bottom to top with your hand on the rail. Everywhere your hand would fall off the rail or hit something, there's a fitting you probably didn't count. Then run the whole thing against a steel estimating checklist before pricing.
Where SteelFlo helps: stair and rail callouts are scattered across plans, sections, and blow-up details, usually in small text on crowded sheets. SteelFlo finds every member callout on every page — the C12x20.7 stringers on the section, the HSS2x2 posts in the detail bubble — and draws a box around each occurrence so you verify the count on the drawing itself, nothing inferred. Detections resolve against 4,500+ sections across 6 standards, and with human verification the combined accuracy runs 95–99%. You still make the judgment calls on extensions and returns; the machine just makes sure no callout goes uncounted.
Quick answers
What channel is used for stair stringers? C12x20.7 is the commercial default; MC12x10.6 for a slimmer profile; plate stringers for architectural work.
How much does a steel stair cost per flight? Roughly $1,500–$4,500 fabricated for a standard commercial pan flight, or $150–$400 per riser. Ornamental stairs cost multiples of that.
How high is guardrail vs handrail? Guardrail 42 inches at open edges; handrail 34–38 inches, graspable, both sides of most commercial stairs.
Do I count handrail extensions? Yes — 12 inches beyond the top riser and a tread depth plus 12 inches at the bottom, per rail, per flight, plus returns.
Is concrete fill in the stair fabricator's scope? Usually not, but specs vary — state it explicitly in your quote either way.
Need weights for stringers, posts, and rail fast? The free steel weight calculator covers channels, HSS, and pipe from the full catalog — or browse every section at /shapes.