Stair
Smith.
See the cuts.
The fastest stair calculator on iOS. Live elevation diagram, instant code compliance, print-ready PDF cut sheet. Built for builders, DIYers, and dads with a saw.
Tap any (i) to learn what it means. Tap the diagram to make it fill the screen, or hit “Show at Saw” for the framing-square layout — the marks you make on the 2×12, twice.
to stringer marks.
blade at 10".
Slide. Mark. Repeat 15 times.”
Every other stair calculator stops at the riser height. StairSmith bridges from “here's your math” to “here's how to mark the 2×12 right now” — a printable framing-square layout on page 2 of every PDF, plus a fullscreen “Show at Saw” sheet for the workbench.
The same diagram, on page 2 of every PDF. Print it, hand it to the framer, or mark the saw bench.
Pinch, pan, tap any dimension to learn what it means. Fullscreen mode hands you a working drawing.
Riser height, code going, riser count, stringer length — in tabular mono, ready for the saw.
Stringers, treads, risers. Stringer length rounded up to the next standard 2×12 for the order.
The printable layout no other app gives you. Page 2 of every PDF. Mark, slide, repeat.
IRC 2021, IBC 2021, NBC 2020, UK Part K, Australia NCC. Pass/fail on riser, going, 2R+T, headroom.
Diagram, cut list, lumber, framing-square layout, disclaimer. AirDrop, email, or print direct.
One tap.
Switch between IRC residential, IBC commercial, NBC Canadian, UK Part K, and Australia NCC. Pass/fail on riser height, going, 2R+T comfort rule, and headroom. Plus free handrail and guard reminders for whichever code you're working under.
Handrail required: stairs with 4 or more risers must have at least one handrail (graspable, 34–38" above tread nosing).
One job done.
Page 1: elevation diagram, cut numbers, lumber list, compliance summary. Page 2: the framing-square layout — the same one you'd draw with a pencil if you had two more hands. AirDrop it, email it, or print direct.
Yours forever.
No. One-time purchase, $6.99 at launch (going to $9.99). You own it. Tools should be tools, not relationships.
Single-flight straight stairs, five building codes, the framing-square page, and the print-ready PDF. Multi-flight, winders, landings, and isometric view are on the roadmap.
Yes. Everything runs on-device. No network is ever required.
Both. Toggle in settings or per-project. Fractions render like a tape measure — never decimals — so the numbers match what’s on your tape.
On your device, encrypted by iOS. There is no cloud, no account, no server I run that could store them.
Because a stair calculator should not phone home. It should do arithmetic, quickly, and remember what you measured yesterday. That doesn’t need a monthly fee.