ProjectCalc Pro exists for one simple reason: most DIY projects go sideways at the store, not at home. You buy too few tiles and make a second trip, or too much concrete and pay for material you will never use. The math to avoid that is not hard — it is just tedious, and easy to get wrong on the back of a receipt.
Our calculators do that math before you buy. Enter your measurements, and each tool tells you how much material you need, how many bags, boxes, or sheets that means in real store packaging, and roughly what it should cost. Every calculator shows its working — the formula, a step-by-step example, and the assumptions behind the numbers — so you can check our math against your own measurements before money changes hands.
Who this site is for
ProjectCalc Pro is written for DIY homeowners in the United States: people tiling a bathroom floor, painting a bedroom, pouring a small concrete slab, spreading mulch, or planning a deck on a weekend. Measurements default to US units (feet, inches, gallons), with metric equivalents available where they help.
This site is a planning tool, not a contractor. Our calculators estimate quantities and costs for common home projects. They do not replace a licensed professional for structural, electrical, plumbing, or gas work — and we deliberately do not publish calculators for those jobs.
Who runs this site
ProjectCalc Pro is produced and maintained by the ProjectCalc Pro Editorial Team. We are a small, independent publishing team — not a retailer, not a manufacturer, and not affiliated with any home improvement chain. We don’t sell the materials our calculators estimate, which means our only job is to make the numbers as accurate and transparent as we can.
How we work
Accuracy is the whole product here, so we treat it that way:
- Every formula is shown. Each calculator page states the formula it uses and where the key figures come from — for example, standard package yields published by manufacturers, or widely used coverage rates such as 350 square feet per gallon for paint.
- Every calculator is tested. Before a calculator goes live, and whenever its logic changes, we run it against a set of test cases worked out by hand. If a result doesn’t match the hand calculation, the calculator doesn’t ship until we understand why.
- Prices are dated. Cost estimates are ranges collected from publicly available pricing, and each cost table shows when it was last checked. Material prices move; we would rather show you a dated range than a precise-looking number that is quietly out of date.
- Corrections are welcome. If you find a number that looks wrong, tell us through our Contact page. We check every report, and when we find an error, we fix the calculator — not just the page you were reading.
A note on estimates
All results on this site are estimates, and honest ones will always have a margin. Rooms are rarely perfectly square, cuts waste material, and products vary between brands. Our calculators build in standard waste allowances where that is normal practice, and our How We Calculate page explains those assumptions in detail. Please read our Disclaimer before relying on any figure for a purchase.
Thank you for using ProjectCalc Pro. We hope it saves you a trip back to the store.