Shed Builder Pro v3 — Offline Construction Calculator App

Seventeen screens. Thirteen calculators. Zero internet required.

Shed Builder Pro is a complete construction calculator suite in a single file. Open it on your phone at the lumber yard, your tablet in the shop, or your laptop at the kitchen table — it runs in any browser, works 100% offline, and never asks for an account, a login, or a signal.

Roof Framing — Every Common Style

• Gable, Hip, Gambrel, and Mono/Skillion rafter calculators
• Dormer framing and rake wall layout
• Pitch tables, rafter lengths, ridge and overhang math done for you

Structure & Framing

• Floor joist span checker — referenced to conservative published IRC Table R502.3.1(2) values (DF #2, 40/10 psf, L/360), with instant pass/fail and safety margin readout
• Wall framing and stud layout with door & window openings
• Header sizing, rough opening calculator, footing estimator, and stair layout

Full Materials Breakdown

• One-tap lumber list: studs, plates, rafters, ridge, sheathing, and concrete
• Floor joists auto-sized to your shed width from the same span table — with a clear warning when a span needs engineered solutions instead
• Built-in waste factor so your shopping list matches reality

Built for the Job Site

• Five visual themes including two colorblind-accessible modes, plus dark/light/auto
• Big-thumb mobile interface with feet/inch toggles on every input
• Remembers your numbers between sessions

How It Works

Instant download after purchase. One HTML file — save it, open it, build. No installation, no app store, no subscription. Yours forever, updates-proof, works in a dead zone.

Your purchase includes a one-time license code, emailed to you along with your download link. Enter it once when the app first opens and it stays unlocked — after that it runs fully offline, on every device you own.

All structural outputs are general estimates based on widely published industry standards and are provided for planning purposes. Always verify with your local building department for your soil, snow load, wind load, lumber species, and code requirements before you build.