Plan the project, then buy the right amount
Six calculators for common outdoor projects. Each one draws your project, lists what to buy, estimates the cost, and shows exactly where every number comes from: building codes, manufacturer spec sheets and industry guides, each with the date we last checked it.
35 sources citedCode checks for deck spans and wall heightsUS or metric unitsRuns in your browser
Choose a project
Deck boards & framing
Boards, joists, beams, posts and screws, checked against the code span tables.
Roof pitch & shingles
Pitch, roof area, squares, bundles, starter, ridge cap and underlayment.
Concrete slab for a shed
Cubic yards, bags, gravel base, forms, rebar or mesh, and control joints.
Paver patio
Pavers, compacted base, bedding sand, joint sand and edging.
Wood privacy fence
Posts, rails, pickets, post-hole size and bags of concrete.
Retaining wall
Blocks, caps, base gravel, drainage stone, drain pipe and trench size.
Why trust these numbers
- Sourced, not guessed. Structural limits come from the 2024 International Residential Code. Coverage and yields come from the manufacturers’ own spec sheets. Each page lists its sources and the date we checked them.
- Honest about what we don’t know yet. Prices come from a Home Depot store and a landscape yard in your region, with the date we checked. Anything we haven’t checked, prices included, is marked PLACEHOLDER. You can type in your own prices.
- Shows its work. Every page has the formulas, a worked example and the full table of numbers it uses.
- Knows its limits. Deck spans and wall heights are checked against the code, and each page says when to call a professional.
Read more about how we calculate, or see the change log for every update to prices and sources.