Free Home Improvement & Construction Calculators
Plan your project. Buy the right amount.
BuildyWork builds practical calculators and planners for home projects — tools you can actually check the work of, not black boxes that hand you a number and ask you to trust it.
Painting
Paint Calculator
Estimate how many gallons or litres of paint you need for a room, based on its dimensions, doors, windows, and number of coats.
Primer Calculator
Estimate how many gallons or litres of primer you need for a room, based on its dimensions, doors, windows, and number of coats.
Wallpaper Calculator
Estimate how many rolls of wallpaper you need for a room, based on its dimensions, doors, windows, and whether the pattern needs repeat matching.
Flooring
Flooring Calculator
Estimate how many boxes of laminate, hardwood, or vinyl plank flooring you need for a room, based on its dimensions, layout pattern, and box coverage.
Tile Calculator
Estimate how many tiles and boxes you need for a floor or wall, based on area, tile size, grout width, and layout pattern.
Carpet Calculator
Estimate how many square yards of carpet and padding you need for a room, accounting for standard roll widths and seam allowance.
Grout Calculator
Calculate pounds or kilograms of grout from your tile size, grout joint width and depth, and tiled area — using the standard joint-volume formula grout manufacturers use.
Epoxy Floor Calculator
Estimate how many epoxy kits or gallons you need to coat a garage or basement floor, from floor dimensions, coats, and your product's stated coverage.
Walls & Masonry
Drywall Calculator
Estimate how many drywall sheets you need for a room's walls and ceiling, based on surface area, sheet size, and a waste factor for cuts and openings.
Concrete Calculator
Estimate cubic yards of concrete and equivalent 60lb or 80lb pre-mix bags for a slab, footing, or post hole, from length, width, and thickness.
Brick Calculator
Estimate how many bricks you need for a wall from its length and height, with door and window openings, a waste allowance, and an adjustable bricks-per-square-foot rate.
Concrete Block Calculator
Work out how many concrete blocks (CMU) you need for a wall from its length and height, using the standard 8×16 block face, an adjustable rate, and a waste allowance.
Rebar Calculator
Calculate the rebar grid for a concrete slab: bars in each direction at 12, 16, or 18 inch spacing, total linear feet with lap-splice allowance, and 20-ft stock bars to buy.
Retaining Wall Calculator
Estimate retaining wall blocks and cap blocks from wall length and height, with your block's actual face dimensions as inputs and a waste allowance for cuts and curves.
Framing
Stud Calculator
Work out how many wall studs and how much plate lumber you need from wall length and stud spacing (16" or 24" on center), with allowances for corners, T-intersections, and openings.
Plywood Calculator
Estimate how many 4×8 (or 4×10) sheets of plywood or OSB you need to sheath a wall, floor, or roof, from the area to cover plus a cutting-waste factor.
Stair Calculator
Lay out a straight stair flight from its total rise: number of risers, equal riser height, tread count, and total run — using the IRC's riser and tread limits.
Baseboard Calculator
Estimate the linear feet of baseboard a room needs from its perimeter minus doorways, plus a miter-cut waste factor — converted into 8 ft or 12 ft trim sticks to buy.
Roofing & Comfort
Shingle Calculator
Estimate how many bundles of asphalt shingles your roof needs from its footprint, pitch, and waste allowance — in roofing squares and whole bundles.
Roof Pitch Calculator
Convert any rise and run measurement into roof pitch (X/12 notation), roof angle in degrees, and the pitch multiplier that turns footprint area into true roof area.
Insulation Calculator
Estimate how many bags or rolls of batt insulation you need for an attic or walls, from the area to insulate and your product's coverage per bag.
BTU Calculator
Size a room air conditioner in BTU/hr from your room's area, sun exposure, kitchen use, and occupants — using the published Energy Star sizing method.
Landscaping
Mulch Calculator
Estimate how many cubic yards or bags of mulch you need for your garden beds, based on bed size, number of beds, and desired depth.
Gravel Calculator
Estimate how many cubic yards and tons of gravel you need for a path, base, or driveway, based on area and desired depth.
Grass Seed & Sod Calculator
Estimate how many pounds of grass seed or how many sod rolls you need for your lawn, based on its area and grass type.
Paver Calculator
Estimate how many pavers you need for a patio or walkway from your area and paver size, with the right waste allowance for straight, curved, or diagonal layouts.
Topsoil Calculator
Estimate how many cubic yards or bags of topsoil you need for a lawn, garden bed, or leveling job, from your area and depth — with bag sizes from 0.75 to 2 cu ft.
Sand Calculator
Estimate how many cubic yards and tons of sand you need for paver bedding, a sandbox, or leveling, from your area, depth, and the sand's moisture-dependent density.
Exterior
Fence Calculator
Estimate how many fence posts, rails, and pickets you need for a wood fence, based on its length, height, and spacing.
Deck Board Calculator
Work out how many deck boards to buy from your deck's dimensions, board size (5/4×6, 2×6, 2×4), board gap, standard board length, and waste allowance.
Siding Calculator
Estimate siding in squares (1 square = 100 sq ft) from your house's dimensions, minus doors and windows, with a 10% or 15% waste allowance by layout complexity.
Driveway Sealer Calculator
Estimate how many 5-gallon pails of asphalt driveway sealer to buy from your driveway's dimensions, number of coats, and your pavement's coverage rate.
Formulas disclosed
Every calculator shows its formula and assumptions on the page, next to the result.
Sources cited
Every constant a tool uses is named and linked to its published source.
Every input editable
Any number that changes your result is exposed and adjustable — nothing is hidden.