Construction Calculator
All-in-one construction calculator
This free construction calculator replaces a drawer full of single-purpose apps. Work in imperial or metric, tap any result to switch units (including concrete in cubic yards, cubic metres, litres or bag counts), and jump between jobs from the "What are you working on?" picker or the dropdown at the top. Everything runs in your browser with no account and no backend, so it keeps working offline.
Concrete calculator
Enter a slab or footing length, width and thickness for volume in cubic yards and cubic metres, plus 30 kg / 25 kg / 80 / 60 / 40 lb bag counts with an adjustable waste factor.
Roof pitch calculator
Find roof pitch as X-in-12, degrees and percent slope, plus rafter length per foot of run, from rise and run or from an angle.
Framing and stud spacing
Lay out studs or joists on-center (16", 24" or any spacing) for the member count and leftover, or size lumber with the board-feet tool.
Drywall and paint estimator
Estimate drywall sheets, compound, tape and screws, and paint by coats for walls, ceiling and trim, netting out doors and windows.
Stair calculator
Get code-aware risers, riser height, tread run, total run and stringer length using NBC/OBC or IRC presets, all editable.
Area and volume
Square footage and cubic footage in imperial or metric, with waste and piece/sheet coverage for quick material counts.
Square-up and diagonal
Check a layout is square with the 3-4-5 rule, or find the exact diagonal or brace length.
Room and project estimator
Build a shopping list for one room, or a full trade-by-trade material takeoff for a new build or renovation, with an interactive floor-plan and 3D view.
Construction calculator FAQ
How do I calculate how much concrete I need?
Open the Concrete tool, enter length by width by thickness, and it returns cubic yards, cubic metres and bag counts with an adjustable waste percentage. Tap the result to switch units.
Does it do roof pitch, framing and drywall too?
Yes. It is one calculator for the whole job (concrete, roofing, framing, drywall, stairs, area and volume), so you do not need a separate app for each.
Can it estimate a whole project or a single room?
Yes. The Room Estimator is free and lists the materials for your rooms. The Project Estimator, which gives a full trade takeoff for a build or renovation along with floor-plan drawing and a 3D view, is part of the $29 Pro unlock.
Does it work in metric and imperial, online and offline?
Both systems, with a per-result unit toggle, and it runs entirely in your browser: no account, works offline, and the calculators are free forever.