Stair & Rafter Calculator

Draw your stringer before you cut it. SiteCalc is a stair calculator, rafter
calculator, concrete calculator and deck calculator in one app — and every
answer comes with a to-scale diagram, in feet, inches and real fractions.

A construction calculator built for the job site, for carpenters, framers,
deck builders and DIYers: no account, no permissions, and it works offline in a
basement with no signal.

WHAT MAKES IT DIFFERENT

• Live diagram on every calculator. Type a total rise and watch the stringer
redraw, notch by notch, with the rise, run and angle labelled.
• Feet-inches-fractions keypad. Enter 5' 7-3/8" in six taps. No decimals, no
converting in your head.
• Works with no signal. All the maths runs on your phone.
• Text the cut list to your crew. One tap turns the diagram and results into an
image you can send from your phone.

THE CALCULATORS

• Stairs — stringers, riser height, tread depth, total run, stair angle, and a
code check against typical IRC residential limits
• Rafter & Roof — common rafter length, plumb and seat cuts, pitch in n:12,
degrees and percent, roof area and shingle bundles
• Concrete — slabs, footings and tube forms, in cubic yards and bags
• Deck — decking boards, rows, joists and screws
• Fence — posts, pickets, panels, rails and concrete per hole
• Board Feet — a running lumber tally with cost
• Drywall — sheets, screws, tape and joint compound
• Paint — gallons by coats and coverage
• Tile & Flooring — tiles, boxes, thinset and grout, by pattern
• Wall Framing — studs, plates and openings

WORKS THE WAY YOU DO

Save any calculation as a project and reopen it on site. Switch between
imperial and metric at any time — saved jobs simply re-render, nothing is
converted or lost. Set fraction precision from 1/4 down to 1/32. Keep the
screen on while your hands are full. Dark mode for early mornings.

NO ACCOUNT, NO PERMISSIONS, WORKS OFFLINE

SiteCalc requests no runtime permissions — no location, no camera, no storage,
no contacts. Nothing you type ever leaves your phone, and every calculation
works with no signal at all.

SiteCalc is free and supported by ads: a banner along the bottom of a
calculator, an occasional full-screen ad between calculators, and an optional
short ad when you share a cut list — if you would rather not watch that one,
the share still works.

SiteCalc provides material and layout estimates for planning only. Results are
not engineering or code advice. Building codes vary by location — verify
requirements with your local authority, and always confirm measurements before
cutting or ordering.

Recent changes:
First release.

Ten job-site calculators with live, to-scale diagrams: stairs, rafters, concrete, decking, fencing, board feet, drywall, paint, tile and wall framing.

• Feet-inches-fractions keypad — enter 5' 7-3/8" in six taps
• Works completely offline
• Save jobs as projects and reopen them on site
• Share the cut list as an image
• Imperial or metric, 1/4" to 1/32" precision