The Build Calculator

Measure twice.
Order exactly once.

Free calculators that turn your measurements into a shopping list — cubic yards, tons, bags, sheets and boards. No signup, no fluff, just the number you came for.

Browse all calculators

Landscaping

Bulk material quantities for yards, beds and outdoor projects.

Concrete & Masonry

Slabs, block, brick and rebar — from base layer to finished wall.

Concrete CalculatorCalculate concrete for slabs, footings and columns in cubic yards, plus how many 60 lb or 80 lb bags to buy, with waste factor and cost estimate.Gravel Under Concrete Slab CalculatorCalculate how much gravel you need under a concrete slab in tons and cubic yards, including compaction allowance, recommended base depths and cost.Asphalt CalculatorEstimate asphalt tonnage for driveways and paths from area and thickness.Paver CalculatorWork out how many pavers you need for a patio or path, plus the gravel base and bedding sand underneath, with waste factor and cost estimate.Rebar CalculatorCalculate how many pieces of rebar you need for a concrete slab from grid spacing, with total linear feet, lap splices and 20 ft sticks to buy.Mortar CalculatorWork out how many bags of mortar you need to lay brick or concrete block, with coverage per 80 lb and 60 lb bag and mixing tips.Brick CalculatorCalculate how many bricks you need for a wall from its size and brick type, plus the mortar bags to lay them, with waste factor and cost estimate.Concrete Block CalculatorWork out how many concrete blocks (cinder blocks / CMUs) you need for a wall, plus mortar bags and core-fill grout, with cost estimate.Sonotube CalculatorCalculate concrete for Sonotube round forms: cubic yards and 80 lb / 60 lb bags per tube by diameter and depth, for deck footings and posts.Retaining Wall CalculatorCalculate retaining wall blocks by course, plus base gravel, drainage stone and cap blocks, with cost estimate and build-height guidance.

Carpentry & Roofing

Framing, siding, fencing and roof math that matches the framing square.

Stair CalculatorCalculate stair rise and run, number of steps and stringer length from total rise.Board Foot CalculatorCalculate board feet from thickness, width and length, for one board or a full order.Rafter CalculatorCalculate common rafter length from run and roof pitch, including overhang.Roof Pitch CalculatorCalculate roof pitch from rise and run, convert pitch to degrees, and find slope multipliers for estimating roofing materials.Roofing CalculatorEstimate your full roofing job: squares of roof area from footprint and pitch, shingle bundles, underlayment, nails and total material cost.Shingle CalculatorWork out how many bundles of shingles you need from roof area, with waste by roof complexity, starter strip and ridge cap counts.Siding CalculatorCalculate siding in squares and panels from wall measurements, minus doors and windows, with waste factor and cost estimate for vinyl and fiber cement.Board and Batten CalculatorPlan a board and batten wall: number of battens and their exact spacing for any wall width, board coverage, and lumber shopping list.Fence CalculatorWork out everything for a wood fence: posts by spacing, rails, pickets with gaps, and concrete bags per post hole, with cost estimate.Deck CalculatorCalculate decking boards, joists, beams and screws for any deck size, with joist spacing options, waste factor and material cost estimate.Plywood CalculatorWork out how many 4x8 plywood or OSB sheets you need for floors, walls and roofs, with waste factor and cost per sheet.

Interior

Walls, floors and finishes, estimated the way the trades do it.

Why The Build Calculator?

Every calculator here answers a real job-site question the way a tradesperson would: in the units suppliers actually sell. You don't need cubic feet — you need to know how many tons of gravel to order, how many 80 lb bags fit in the trunk, and whether bulk delivery beats bags this time.

Results update as you type, formulas are shown so you can check the math, and every page includes the reference tables — densities, coverage rates, code limits — that the pros keep in their heads. Estimates only: confirm final quantities with your supplier.