About ProjectMath

ProjectMath publishes home improvement cost calculators and guides with one rule: every number has a source and a date. Many DIY sites publish "average costs" that are years old, contradict themselves or have no source. We built this site to fix that.

Editorial standards

• Each price links to where it came from and shows when we checked it.
• When sources disagree, we show the range and explain why.
• If we can't source a figure, we leave it out.
• Prices are reviewed on a schedule: weekly for the lumber index, quarterly for the guides.

Advertising

ProjectMath is supported by display advertising. Advertisers have no influence on our content or figures.

Contact

Corrections and feedback: corrections@projectmathhq.com

Last reviewed: 2026-10-14. Prices are national planning ranges; get local quotes.