Article
Introducing Carpentry Calculator — Jobsite Math, Ready On Site
Why we built Carpentry Calculator: twelve offline jobsite tools for stairs, rafters, lumber, and layouts — no subscription, no ads.
If you have ever climbed down from a roof framing job, opened a generic calculator app, and tried to enter 14' 6-3/8" without fighting the keyboard, you already know the problem this site exists to solve.
Carpentry Calculator is an iPhone app — and this website is its home — built for carpenters, framers, remodelers, builders, and serious DIY woodworkers who measure in feet, inches, and fractions on North American jobsites.
Why another carpentry calculator?
Construction math apps used to be straightforward: buy once, carry in your tool belt, and trust the fractions. Lately, many competitors moved to subscriptions and packed in ads. On a jobsite, that is the wrong trade.
We built Carpentry Calculator with three non-negotiables:
- Core calculators work offline. Stairs, rafters, board feet, stud layout, sheet goods, concrete, square-up, unit conversion, fractions, feet-inch tape, job takeoffs, and crown miter — all twelve run without cell service.
- No subscription. Optional Pro is a one-time purchase for workflow upgrades like unlimited saved records and diagram PDF exports.
- Feet-inch-fraction native input. Type measurements the way your tape reads. Results round to 1/16” by default and show both fraction and decimal forms.
What is in the app
Each calculator is form-based with a diagram, formula reference, and a clear disclaimer: verify before you cut.
| Calculator | What it solves |
|---|---|
| Stair Stringer | Risers, treads, total run, stringer length, IRC reference warnings |
| Rafter / Roof Pitch | Common rafter length, rise, pitch angle, plumb cut, seat cut, roof area |
| Board Feet | Nominal lumber volume, quantities, and cost |
| Stud / Joist Layout | On-center count, mark positions, openings, plate estimates |
| Sheet Goods | Drywall, OSB, plywood sheet counts with waste |
| Job Takeoff | Material quantities, waste, units, and line-item cost |
| Concrete Volume | Cubic feet, cubic yards, bag counts |
| Square-up Diagonal | 3-4-5 layout checks |
| Unit Converter | Feet-inch-fraction, decimal, and metric |
| Fraction Calculator | Fraction arithmetic with simplification |
| Feet-Inch Tape | Add and subtract jobsite dimensions |
| Crown Miter | Flat crown molding miter and bevel settings |
Free vs Pro
Every core calculator is free and offline. Pro ($9.99 one-time in the US App Store) adds project-based job records, diagram PDF exports for your crew, custom IRC reference limits, and future Pro updates. The free version saves up to five calculation history entries.
About this website
This site gives you:
- An overview of every carpentry calculator tool in the app
- Support for download links and contact options
- Privacy Policy and Terms of Service that match what the app actually does — local storage, no tracking, RevenueCat for Pro purchases only
When you are ready, download Carpentry Calculator on the App Store and keep twelve jobsite tools in your pocket — offline, with no ads interrupting your work.