Contact
Corrections are the most useful thing you can send.
Everything comes to one address: hello@example.com. There is no contact form here on purpose — a form means storing your details on a server, and the whole point of this site is that it does not do that.
Reporting a wrong figure
This is the most valuable kind of message. To make it actionable, include the calculator name, the numbers you entered, the result you got, and the result you expected — plus where your figure comes from if it is a supplier quote or a product spec sheet.
Bear in mind that densities and coverage rates genuinely vary by region and supplier, so a difference is not automatically an error. Each page lists the figures it used under how we calculate.
Suggesting a calculator
Tell us what you were trying to work out and what stopped you. The specific job is more useful than the calculator name — “how many fence panels for a sloped yard” tells us more than “fence calculator”.
Business enquiries
Advertising, partnership and licensing enquiries go to the same address. Please put the word “business” in the subject line.