Stringline - Construction Calc
Stair Rafter Concrete Framing
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
14 construction calculators built for the job site. Stairs, concrete, rafters, right triangles, and more. Try everything free — unlock Pro once, own it forever.
Construction calculator that works in feet, inches, and fractions — matched to 1/64". Download for free. No subscription. No ads. Works offline.
14 SPECIALTY CALCULATORS
Stair Layout — rise, run, stringer, angle. IRC and OSHA code check built in.
Concrete — cubic yards and bag counts for slabs, footings, columns.
Rafter Length — common, hip/valley, jack. Plumb cut, seat cut, overhang.
Equal Spacing — every position for studs, balusters, posts, joists.
Compound Miter — blade tilt and miter angle for crown and trim.
Studs / OC — count and positions for any wall at 16" or 24".
Pitch / Slope — pitch, degrees, grade, and roof factor.
Baluster Spacing — count, gap, and positions. IRC 4" sphere test built in.
Board Feet — lumber volume from nominal dimensions.
Drywall Estimator — sheets, waste factor, and opening deductions.
Roofing Calculator — squares, bundles, and sheathing for any roof pitch.
Right Triangle — check square on any corner. Two sides in, all angles out.
Area & Volume — rectangles, circles, triangles, trapezoids.
Conversions — feet-inches, decimal feet, metric.
HOW IT WORKS
Three calculators are yours to keep — Right Triangle, Area & Volume, and Conversions — with the full keypad, memory, and paper tape. No limits, no catch.
The other 11 Pro calculators (stairs, concrete, rafters, and more) come with 5 uses so you can try them on a real job. One purchase unlocks everything permanently.
YOUR TAPE READS FRACTIONS. SO DOES STRINGLINE.
Enter 12' 3-1/2" exactly how you say it. No converting to decimals, no rounding surprises. Integer 64ths arithmetic — every answer matches your tape, not a floating-point guess.
BUILT TO BE TRUSTED
• Shows the math — step-by-step so you can verify every answer
• IRC and OSHA validation with code section citations
• Every formula verified against building code standards before release
• Paper tape and full calculation history
• PDF export with Show My Work steps
• Works completely offline — no internet, no accounts
No subscription. No ads. Built for tradespeople who can't afford a wrong number.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Stringline is now free to download. Try stairs, concrete, rafters, and 11 more calculators on your next job.
- 5 free uses across Pro calculators — try before you buy
- Right Triangle, Area, and Conversions are always free with no limits
- One purchase unlocks everything forever — no subscription
- PDF export with Show My Work steps
- Light, dark, and auto appearance modes
- Project tagging — organize calculations by job
The developer, Hector Sahagun, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Hector Sahagun
- Size
- 21.8 MB
- Category
- Utilities
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Stringline Pro $2.99
- Copyright
- © 2026 Stringline
