Free construction calculators
Measure twice. Buy once.
Concrete, paint, roofing, fencing and more. Type in your measurements, get the number you need, and get back to work.
Popular calculators
Concrete Slab Calculator
Cubic yards and bags of concrete for a slab, patio, or pad.
Gravel Calculator
Cubic yards and tons of gravel for a driveway, path, or pad.
Paint Calculator
Gallons of paint needed for a room, minus doors and windows.
Wallpaper Calculator
Rolls of wallpaper needed for a room or accent wall.
Drywall Calculator
Sheets, joint compound, screws, and tape for a room.
Plywood Subfloor Calculator
Sheets, screws, and adhesive for a plywood or OSB subfloor.
Fence Calculator
Posts, pickets, rails, and concrete for a wood fence.
Roofing Shingle Calculator
Squares and bundles of shingles from footprint and pitch.
Insulation Calculator
Packages of insulation from area and the coverage on the label.
Air Conditioner BTU Calculator
Cooling capacity for a room by size, sun, kitchen, and people.
Browse by category
Concrete & Landscaping
Cubic yards, tons, and bags for concrete, gravel, and mulch projects.
Paint & Finishes
Gallons and rolls for paint, deck stain, and wallpaper jobs.
Walls & Floors
Sheets, boxes, and finishing materials for interior surfaces.
Outdoor Structures
Lumber, shingles, and hardware counts for fences and roofs.
Home Systems
Insulation coverage and cooling capacity for comfortable rooms.
Built to be checked
Material estimates go wrong in two ways: the formula is hidden, or the assumptions are. Each calculator here states both. You will see the exact arithmetic in the results notes, the standard allowances (like 21 square feet per door), and the waste factors, and you can change any assumption that does not match your project.
The defaults reflect common US materials and practices: 80 lb concrete bags, 350 square feet per gallon of paint, three shingle bundles per square. Prices and product sizes vary by region and brand, so treat every result as a strong starting point for your shopping list, then confirm against the packaging or your supplier before ordering.
The name is borrowed from the trades: a takeoff is the step where a builder counts every material a job needs before buying. These calculators do that step for you.