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Home project calculators that show their math

Boards, pickets, tiles, sheets and stringers — every calculator here prints its formula, its assumptions and a worked example on the same page, so the number at the hardware store is one you can check, not one you have to trust.

Quick estimator

Pick a project and a size — a rough count appears here; the full material list is in each tool.

5
calculators live today
37
calculators in the full plan
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formulas shown on-page
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cost — no account, ever

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Outdoor · Framing & boards

Deck Calculator

Free deck calculator: enter deck size and board type to get deck boards, joists, screws and concrete footings — with the…

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Outdoor · Fencing

Fence Calculator

Free fence calculator for wood fences: posts, rails, pickets and concrete bags from your fence length, height and style.…

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Interior · Tile & stone

Tile Calculator

Free tile calculator: tiles and boxes needed by tile size, plus thinset and grout bags, with cuts and breakage waste inc…

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Interior · Walls & ceilings

Drywall Calculator

Free drywall calculator: sheets needed for walls and ceiling, plus screws, joint compound and tape. Deducts doors and wi…

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Framing · Stairs

Stair Calculator

Free stair calculator: from total rise to riser count, exact riser height, treads, total run, stringer length and angle …

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Why these numbers hold up

Most calculator sites hide the method and round in their own favour. Here, each page carries the same four things: the formula in plain words, a worked example with real arithmetic you can follow on paper, the assumptions (board widths are actual sizes, not nominal; waste is a number you choose, not one we smuggle in), and the sources for every coverage rate. If a number is a rule of thumb, the page says so.

A wooden deck under construction — boards being laid over joists
Every tool here answers the same question you ask at the lumber counter: how many do I buy? The counts include the waste, the gaps and the cuts — not just the geometry.

What is being built next

The concrete family (a 301,000-search-a-month head term), bulk materials — mulch, topsoil and sand — plus asphalt, board foot and more indoor finishes are already researched, grouped and planned in waves, each with the same standard: deep pages, shown formulas, real diagrams. The five calculators above are the pilot wave; they are live now so their numbers can be checked against real projects.