About Blueprint Calc

Blueprint Calc is a free tool to help DIY homeowners and contractors buy the right amount of material the first time. No signup. No ads written into the calculator results. No tracking cookies.

How we calculate

Every calculator uses industry-standard formulas from the sources professionals actually trust — the IRC (International Residential Code), manufacturer install guides (Trex, TimberTech, Quikrete, USG, CertainTeed, Sherwin-Williams, Behr), and published coverage specs from the major paint, mulch, concrete, and lumber brands.

Where industry sources disagree, we pick the conservative value — a coverage rate toward the lower end of the published range, a waste factor toward the upper end. The cost of a return trip to Home Depot is higher than the cost of one extra gallon of paint.

When a formula involves engineering judgment (joist spacing for composite decking, short-load fees on ready-mix concrete, subgrade prep requirements), we cite the decision path in the How we calculated it section on every calculator page.

Who's behind this

Blueprint Calc is built by a small independent team that has collectively worked across residential construction, software engineering, and technical writing. We are homeowners ourselves. Every calculator on this site is something one of us needed to solve for a real project — and we got tired of the dated calculator sites that either under-buy (leading to a second trip to the store) or over-buy (wasting hundreds on unused material).

We are not a licensed contractor, engineer, or architect. For projects that require structural design, permit drawings, or code compliance sign-off — decks over 30", load-bearing framing, anything touching water or electrical — hire a licensed professional. Use our calculators for material quantities and cost ballparks.

How we update

Industry constants drift over time: bag yields change when Quikrete tweaks a formulation, code minimums update every three years with a new IRC cycle, ready-mix pricing responds to fuel and cement markets. We re-verify every calculator's numbers at least annually and flag the last-updated date on each How we calculated it section.

If you find a number that looks wrong, tell us. We fix verifiable errors within 48 hours. Corrections are logged in our git history so you can see exactly what changed and why.

How we make money

The calculators are and will always be free. We make money three ways:

• Affiliate commissions on the "what you'll need to buy" shopping list at the bottom of each calculator. If you click through to Home Depot, Lowe's, or Amazon and buy something, we earn a small commission — at no extra cost to you. See the full affiliate disclosure.
• Lead-generation referrals on higher-ticket projects (decks, window replacement, concrete pours over 2 yards). If you request free quotes through a CTA on the site, our referral partner (Angi, Modernize, or similar) pays us for the match — again, no extra cost to you.
• Display advertising. If you see ads on the site they are from Google AdSense or a comparable network. We limit ads to three slots per page and never break up the calculator itself with inline ads.

What we do not do: sell your data, require signups, lock features behind a paywall, auto-generate thin content with AI, or run native-advertising sections that pretend to be editorial content.

Get in touch

Bug reports, math corrections, partnership questions, feature requests — all welcome at our contact page.