About The Build Calculator

The Build Calculator is a free collection of construction and landscaping calculators built for homeowners, DIYers and tradespeople. Each tool answers one practical question — how much gravel, how many sheets of drywall, how long a rafter — in the units suppliers actually sell.

How our calculators work

Every calculator uses the standard industry formulas and material densities that estimators and suppliers use, and each page shows its formula so you can verify the math yourself. We include the reference tables (coverage rates, densities, code limits) alongside every tool so you understand the number, not just receive it.

Accuracy and limitations

All results are estimates for planning and budgeting. Real-world quantities vary with site conditions, compaction, moisture and product differences — always confirm final quantities with your supplier, and check local building codes before construction. If you spot an error, please tell us and we'll fix it.

How the site is funded

The Build Calculator is free to use and supported by advertising. Ads never affect the results our calculators produce.