Contact us

Found a mistake, want a new calculator, or have a question about a result? We'd like to hear from you.

We usually reply within two business days. When reporting a problem with a calculator, please include the page, the numbers you entered and the result you expected. That lets us reproduce and fix it quickly.

Please note

We can't provide engineering, structural or building-code advice for a specific property. For structural work, consult a licensed professional and your local building department.
We don't sell materials and aren't affiliated with any store or manufacturer.