About BuildCalc & our methodology

BuildCalc builds free material calculators for U.S. homeowners and contractors. Every tool is designed to answer one question well: how much material does this job take, and how do I order it?

Where our numbers come from

Our calculators are built on published, verifiable data — not estimates pulled from thin air:

• Density constants (asphalt 145 lb/ft³, concrete 150 lb/ft³, gravel and sand ~100 lb/ft³, topsoil ~80 lb/ft³) are standard industry figures cross-referenced with bodies like the National Asphalt Pavement Association and the Portland Cement Association.
• Code limits (such as stair riser and tread maximums) reference the International Residential Code.
• Conversions (27 ft³ per cubic yard, bag yields, roofing squares) are exact and shown in the formula on each page so you can check our work.

Our honesty rule on cost

We only show prices we can source. Where a material has a public listed price, we cite the source and the month it was collected. For installation and labor cost, real quotes vary by 50% or more depending on region, access, and scope — so we do not invent a "national average." Instead we point you to published cost guides and to free quotes from local contractors. If we can't source a number, we don't display it.

Accuracy & updates

Estimates are for planning only. Always confirm final quantities with your supplier and follow local code and manufacturer specs. We review our density data and any listed prices quarterly. Found an error? Email us and we'll fix it.

Contact

Questions, corrections, or partnership ideas: JaydenHall1962@hotmail.com.

Last updated: January 2026.