About BuildyWork

BuildyWork builds calculators and planners for home projects — tools you can actually check the work of, not black boxes that hand you a number and ask you to trust it.

How every calculator is built

Every tool on this site discloses its formula, its assumptions, and the source of every constant it uses — directly on the page, next to the result, not buried in a separate document. Where a number comes from a published source (a retailer's coverage guidance, a manufacturer's technical data), that source is named and linked in the tool's "How This Works" section. Where a number is a structural assumption rather than an external fact — like the standard door or window size used to calculate wall area — that's disclosed too, so you can judge for yourself whether it fits your situation.

Every input that materially changes a result is exposed and editable. Advanced settings — like a product's specific coverage rate — are tucked behind an "Adjust" toggle so the default experience stays simple, but they're never hidden from someone who wants to fine-tune the estimate for their exact materials.

What these tools don't do

These calculators produce estimates for planning and purchasing — they are not a substitute for a licensed professional's judgment on structural, electrical, plumbing, or code-compliance questions. Where a calculation's model has known limits, the page says so directly in an edge-case or common-mistakes section, rather than presenting a number with unwarranted confidence.

Verification

Each tool's formula and sourced values are checked against their original source before publishing, and the "last verified" date shown on each tool reflects when that check last happened — pulled directly from the same record the formula itself is built from, not typed in separately.

Who checks this

Calculations are reviewed under BuildyWork's editorial verification process: every formula is checked line-by-line against its cited source (a manufacturer's technical data sheet, a building-code reference, a retailer's coverage guidance) before publishing, and re-checked whenever the underlying source changes. Tools that touch structural, load-bearing, or code-governed questions — stair rise and run, retaining wall design, rebar spacing, stud framing, roof pitch, insulation R-value, and HVAC sizing — go through an additional pass against the relevant model code or standard referenced on that page, and carry an explicit scope note describing what the tool does not cover.

Corrections policy

Found a calculation that looks wrong? Report a calculation issuewith the tool name and what you expected — every report is checked against the formula's cited source, not just re-tested against its own output. If the report identifies a real error, the formula is corrected, the fix is verified against the source before publishing, and the tool's "last verified" date is updated to reflect the correction — that date is always the true record of when a formula was last checked, including corrections, not just its original publish date.