Construction Calculators
28 free toolsConcrete, paint, tile, drywall, roofing, decks, fences, and material estimates.
Construction calculators estimate materials for a project before you order: concrete bags or cubic yards, gravel and mulch by the ton, paint and wallpaper with waste, tile and drywall, roofing squares, stair and ramp dimensions that meet code, HVAC BTUs, and a line-item estimate you can export as a PDF. The formulas and coverage figures are cited (Quikrete, USG, IRC, ADA), and every result should still be checked against your supplier and local code.
Everything here runs in your browser: files and text are processed locally and never uploaded. The estimate generator saves drafts only in your browser's local storage.
All 28 tools
Paint Calculator
Gallons of paint for walls and ceilings, minus doors and windows, by coats
Concrete Bag Calculator
Bags of concrete mix or cubic yards for slabs, footings, and posts
Gravel Calculator
Tons and cubic yards of gravel for driveways, paths, and beds
Mulch Calculator
Bags or cubic yards of mulch for beds at any depth
Roof Pitch & Rafter Calculator
Pitch, angle, rafter length, and rise from span and slope
Tile Calculator
Tiles and boxes needed with grout gaps and a waste allowance
Drywall Calculator
Sheets, screws, joint compound, and tape for walls and ceilings
Fence Material Calculator
Posts, rails, pickets, and concrete for a wood fence
Deck Material Calculator
Joists, decking boards, screws, and footings for a deck
Paver Calculator
Pavers, base gravel, and sand for a patio or walkway
Topsoil Calculator
Cubic yards, bags, and tons of topsoil for lawns and beds
Sod Calculator
Rolls or pallets of sod for any lawn shape, with waste
HVAC BTU Calculator
Heating and cooling BTUs for a room by size, climate, and insulation
Insulation Calculator
Batts or rolls needed and the R-value your climate zone calls for
Asphalt Driveway Calculator
Tons of hot-mix asphalt and estimated cost for a driveway
Roofing Shingle Calculator
Squares, bundles, underlayment, and nails from roof size and pitch
Retaining Wall Block Calculator
Blocks, cap units, base gravel, and backfill for a block wall
Pond Liner Calculator
Liner and underlayment size from pond length, width, and depth
French Drain Gravel Calculator
Gravel, pipe, and fabric for a French drain trench
Wallpaper Roll Calculator
Rolls needed by wall size, roll size, and pattern repeat
Board Foot Calculator
Board feet and lumber cost from thickness, width, and length
Stair Stringer Calculator
Rise, run, step count, and stringer length that meet code
Stud Wall Calculator
Studs, plates, and headers for a framed wall
Pipe Volume Calculator
Volume and water weight inside a pipe by diameter and length
Ramp Slope Calculator
Ramp length, angle, and ADA compliance from rise and run
Gutter Size Calculator
Gutter and downspout size from roof area, pitch, and rainfall
AC Tonnage Calculator
Air conditioner size in tons and BTUs for your home
Construction Estimate Generator
Build a line-item construction estimate and download it as a PDF
Guides
From the blog: the mechanisms, standards, and edge cases behind these tools.
- Cubic Yards, Tons, and Density: Ordering Gravel, Soil, and Mulch Area × depth in inches ÷ 12 ÷ 27 gives cubic yards; density turns yards into tons. The real numbers for gravel, soil, mulch, asphalt, concrete bags, and sod. Sep 27, 2026 · uses Concrete Bag Calculator, Gravel Calculator, Mulch Calculator +7
- Paint, Wallpaper, Tile: How Much to Buy and Where the Waste Goes Why one gallon per 400 sq ft under-orders, how pattern repeats eat wallpaper, and the tile, grout, thinset and drywall figures, each worked for a real room. Sep 26, 2026 · uses Paint Calculator, Tile Calculator, Drywall Calculator +3
- Roof Pitch to Degrees: Chart, Formula, and the Multiplier for Ordering Shingles 4/12 is 18.43 degrees, 6/12 is 26.57, 12/12 is 45. Full chart with roof-area multipliers so you can turn a footprint into squares of shingles. Oct 13, 2026 · uses Roof Pitch & Rafter Calculator, Roofing Shingle Calculator, Stair Stringer Calculator +2
- How to Calculate Board Feet (and Why a 2x4 Isn't 3.5 of Them) Board feet = thickness x width x length / 144. Softwood is tallied on nominal size, so a 2x4x8 counts as 5.33 BF but holds 3.5. Worked table inside. Oct 13, 2026 · uses Fence Material Calculator, Deck Material Calculator, Board Foot Calculator
- How Long Does a Propane Tank Last? The BTU Math, Worked Out A 20 lb tank holds about 4.7 gallons, or roughly 431,600 BTU. Divide by the burner's BTU/h to get hours. Worked examples for grills, heaters, generators and furnaces. Sep 29, 2026 · uses HVAC BTU Calculator, AC Tonnage Calculator