About Builder's Math

Builder's Math is a set of free calculators for building and DIY projects: concrete, gravel, topsoil, mulch and asphalt, square footage, tile, drywall, paint, stairs, roofing and lumber. Each one gives the answer in the units you buy materials in, and shows the formula, a worked example and the sources behind its numbers so you can check it.

The calculators run in your browser. There is no account, and the numbers you type are not sent anywhere.

Results are estimates for planning. Check local building codes and your supplier’s figures before you order or build.