StructCalc is a professional construction calculator built by a carpenter. It handles rafter calculations, stair design, baluster spacing, right-angle verification, and on-site dimensional math — all in one free app.

Calculator Tools

Rafter & Roof Framing
Calculate common rafters, hip rafters, and roof angles instantly. Enter pitch, run, or rise, and get rafter lengths, plumb cuts, seat cuts, and material quantities. No more pencil-and-paper trig on the jobsite.

Stair Design
Design safe, well-designed stairs from a single input — total rise. StructCalc calculates tread count, riser height, stringer length, and headroom automatically.

Baluster Spacing
Calculate equal baluster spacing for railings, fences, and decks. Adjust spacing and post positions until the layout looks right.

Square Check (Pythagorean Theorem)
Verify right angles for foundations, walls, and framing layouts. Enter any two sides of a triangle and get the third instantly — with a real-time diagram that updates as you type.

Dimensional Calculator
A full feet-inch-fraction calculator for experienced builders. Add, subtract, multiply, and divide in imperial or metric without converting to decimals. Trigonometry mode handles sine, cosine, and tangent for any angle.

Measurement Series
Run cumulative measurements for long layouts — foundation footings, wall plates, deck joists. No need to keep a running total in your head.

Project Management

Group your calculations into real projects with material estimates, notes, and status tracking. Create material profiles with unit prices and reuse them across jobs. Quick-export material lists for procurement.

Features

- Works in Metric (mm, cm, m) and Imperial (feet, inches, fractions)
- Dark mode and light mode — follows system setting or manual override
- Free to use with optional premium upgrade for unlimited project storage
- Real-time visual diagrams for stairs, rafters, and right triangles
- Calculation history with searchable logs
- Material catalog with user-defined profiles and suppliers

Who Is StructCalc For?

- Carpenters and framers
- General contractors and builders
- Roofers and siding installers
- Deck and fence builders
- DIY homeowners and hobbyists
- Architects and designers

Why Choose StructCalc?

- Fast. Instant results. No manual math.
- Accurate. Built for real jobsite tolerances.
- Free. Professional features without a subscription.
- Offline. Works anywhere — no internet connection required.
- Clean. Modern interface that doesn't get in your way.

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Built by a carpenter. For every builder.

Download StructCalc free today.