27 free calculators

Construction calculators
that show their working

Cubic yards, bag counts, roofing squares and material quantities in seconds. Every tool explains the formula it uses, so you can check the number rather than trust it.

27Calculators

5Trades covered

FreeNo sign-up, no app

Concrete

Volume, bag counts, rebar and cost for slabs, footings, columns, driveways and stairs.

Concrete Slab CalculatorCubic yards and bag counts for any rectangular slab.Concrete Bag CalculatorHow many 40, 60 or 80 lb bags of concrete do you need?Concrete Driveway CalculatorConcrete volume and area for a driveway pour.Concrete Cost CalculatorEstimate what your concrete will actually cost.Concrete Footing CalculatorVolume for strip footings and foundation trenches.Concrete Column CalculatorConcrete for round columns, piers and post holes.Concrete Stairs CalculatorConcrete volume for a flight of poured steps.Rebar CalculatorRebar quantity and total length for a slab grid.Concrete Pad CalculatorConcrete for shed, HVAC and hot tub pads.

Masonry & Aggregate

Brick, block, mortar, gravel, pavers and asphalt quantities.

Brick CalculatorHow many bricks a wall needs, plus the mortar.Concrete Block CalculatorCMU block counts for a wall, plus mortar and fill.Mortar CalculatorMortar bags for a given number of bricks or blocks.Gravel CalculatorCubic yards and tons of gravel, sand or topsoil.Paver CalculatorPaver counts, base gravel and joint sand for a patio.Asphalt CalculatorTons of hot mix asphalt for a driveway or lot.

Roofing

Roof area, pitch multipliers, shingle bundles and squares.

Roofing CalculatorRoof area, squares and shingle bundles from the footprint.Roof Pitch CalculatorConvert roof pitch to angle, slope and area multiplier.Gutter CalculatorGutter length, downspouts and roof drainage load.

Interior

Drywall, insulation, tile, paint and flooring quantities.

Drywall CalculatorSheets, screws, tape and compound for a room.Insulation CalculatorBatt packs or blown-in bags for walls and attics.Tile CalculatorTile counts, boxes, thinset and grout for any area.Paint CalculatorGallons of paint and primer for a room.Flooring CalculatorBoxes of laminate, vinyl or hardwood for a room.

Framing & Exterior

Deck boards, fencing, framing studs and siding.

Deck Board CalculatorDeck boards, joists and fasteners for a deck.Fence CalculatorPosts, rails, pickets and concrete for a fence run.Stud CalculatorStuds, plates and framing lumber for a wall.Gate Post CalculatorPost size, depth and concrete for a gate.

Why these calculators

Construction material is measured one way and sold another. Concrete is poured in feet and inches but ordered by the cubic yard. Bricks cover an area that depends on the mortar joint, not on the brick. A roof is always larger than the building beneath it, by a factor set entirely by the pitch.

Every result includes a waste allowance. Ordering short costs far more than ordering slightly over — a second delivery, a cold joint, or a colour mismatch between production runs.

Nothing here needs an account and nothing is sent to a server: the calculators run entirely in your browser.