Contact

Email hjjd009@gmail.com and you will get a reply within two business days.

Reporting a wrong number

Please include:

• The calculator and the exact inputs you entered.
• What it returned, and what you expected instead.
• Where your expected figure came from — a product label, a supplier quote or a site plan is ideal.

If the error is real, the page is corrected and the revision date is updated. Verified corrections are credited unless you ask us not to.

Requesting a calculator

Tell us the material, the unit you buy it in, and the one thing that currently forces you to do the math twice. Those three details are what decide whether a tool gets built.

Advertising, licensing and press

Use the same address with a short subject line describing the request. We do not sell links, and we do not publish sponsored tool pages — ads are the only commercial placement on the site.