About Project Cost Math

Project Cost Math is a small, independent site of free calculators for home and yard projects. It is written and maintained by the Project Cost Math team.

Each calculator shows its formula, marks every assumed default (especially prices) and lists its sources. Quantities come from simple geometry and product specifications; prices are typical US assumptions that you can adjust for your state or replace with your own.

Everything here is a rough estimate, not a guarantee and not financial advice. We are not contractors, and nothing here replaces a professional, local building codes or the instructions on a product.

Project Cost Math is not affiliated with any retailer, manufacturer or government agency. See how we calculate and our sources.

Last updated October 22, 2026.