Construction Calculators

ArrayKit's construction calculators turn measurements into material quantities for home and building projects. For anything poured or spread, the Concrete Calculator gives cubic yards, cubic meters and bag counts for slabs, footings and columns, the Gravel Calculator and Mulch Calculator convert an area and depth into tons, cubic yards or bags, the Asphalt Calculator sizes a driveway in tons of hot mix, and the Rebar Calculator counts bars, laps and ties for a slab. Indoors, the Square Footage Calculator calculates area and material cost, and the Paint Calculator, Tile Calculator, Drywall Calculator and Wallpaper Calculator work out gallons or liters, tiles and boxes, sheets with mud and tape, and rolls matched to the pattern repeat. For framing and outdoor builds, the Stud Calculator, Deck Calculator, Fence Calculator, Brick Calculator and Stair Calculator count studs, joists, posts, bricks and steps, and the Board Foot Calculator totals a lumber cut list. The Roofing Calculator turns a footprint and pitch into squares and shingle bundles, the Roof Pitch Calculator converts pitch to degrees and rafter lengths, and the Siding Calculator counts siding squares. The BTU Calculator sizes heating and cooling for a room, and the Insulation R-Value Calculator adds up R-value and heat loss. Homeowners, DIYers, contractors and estimators use them for takeoffs and shopping lists. Every calculation runs in your browser, so your measurements and prices stay on your device.

  • Concrete Calculator — Estimate concrete volume and bags for slabs, footings and columns.
  • BTU Calculator — Estimate the BTU capacity needed to heat or cool a room.
  • Square Footage Calculator — Calculate area in square feet or meters for rooms and projects, with cost.
  • Stair Calculator — Calculate stair rise, run, number of steps and stringer length for a staircase.
  • Roofing Calculator — Estimate roof area, squares and shingle bundles from footprint and pitch.
  • Tile Calculator — Calculate how many tiles and boxes you need for a floor or wall.
  • Mulch Calculator — Estimate mulch volume in cubic yards and bags for a bed and depth.
  • Gravel Calculator — Estimate gravel volume and weight in tons for an area and depth.
  • Paint Calculator — Work out how much paint a room needs from its size, coats, doors and windows.
  • Brick Calculator — Estimate bricks and mortar for a wall from its size, brick type and joint width.
  • Board Foot Calculator — Calculate board feet and lumber cost for a cut list of boards.
  • Drywall Calculator — Estimate drywall sheets, joint compound, tape and screws for a room.
  • Wallpaper Calculator — Rolls needed from wall size, roll size and pattern repeat, the way decorators count.
  • Fence Calculator — Posts, rails, pickets and concrete bags for a fence run, using the fencepost rule.
  • Rebar Calculator — Count the bars, laps, ties and weight of reinforcement for a concrete slab.
  • Asphalt Calculator — Turn a driveway or car park into tons of hot mix, cubic yards and cost.
  • Insulation R-Value Calculator — Add up an assembly’s R-value, U-factor and heat loss layer by layer.
  • Deck Calculator — Boards, joists, footings and screws for a deck, with joist spans checked.
  • Stud Calculator — Count studs, plates, headers and cripples for a wall, openings included.
  • Roof Pitch Calculator — Convert pitch, angle, grade and slope factor, with rafter lengths and roof area.
  • Pipe Volume Calculator — Volume, water weight, fill time and flow velocity for any pipe run.
  • Siding Calculator — Squares, boxes, boards or panels of siding from wall sizes, gables and openings.

Guides

  • How Much Concrete Do You Need? — How much concrete you need for a slab, footing or post hole: volume in cubic yards and m³, 60 lb and 80 lb bag counts, waste allowance, and ready-mix vs bags.
  • How to Calculate Square Footage — How to calculate square footage for rectangles, L-shaped rooms, triangles and circles, convert sq ft to m², add a flooring waste allowance and price per sq ft.

Frequently asked questions

What can I estimate with these construction calculators?
Volumes and weights for concrete, gravel, mulch and asphalt; counts of tiles, bricks, drywall sheets, studs, deck boards, fence posts, wallpaper rolls and siding squares; and dimensions such as stair rise and run, roof pitch and rafter length. There are also sizing tools for heating and cooling in BTU, insulation R-value and heat loss, and the volume of water a pipe run holds.
How do I work out how much concrete I need?
Choose slab, footing or column in the Concrete Calculator and enter the dimensions in feet and inches or meters and centimeters. It returns cubic yards and cubic meters plus the number of 60 lb or 80 lb bags, rounded up, and a quantity field multiplies identical pours. For fence posts, the Fence Calculator converts concrete per hole into 50 lb bags, and the Rebar Calculator counts the steel for a reinforced slab.
Do the estimates include extra material for waste?
Several do. The Tile, Brick, Drywall, Roofing, Deck, Siding, Rebar and Asphalt calculators let you set a waste allowance, and the Wallpaper Calculator counts whole strips per roll so pattern matching is built in. For volumes such as concrete, gravel and mulch, add a margin yourself, round up, and confirm the order with your supplier.
Are my measurements and prices uploaded anywhere?
No. Every construction calculator runs in your browser, so room sizes, cut lists and material prices stay on your device and are not uploaded to ArrayKit.
Do the construction calculators check building codes?
No. They compute quantities and geometry from common rules of thumb and published tables, and a few add checks: the Deck Calculator compares joist sizes with 40 psf span tables, the Stud Calculator suggests header sizes, and the Rebar Calculator checks concrete cover against the usual minimums. Codes vary by jurisdiction, so confirm stairs, structural members and HVAC sizing with your local building department, an engineer or an HVAC professional.