Contact

Found a mistake in a formula, a result that doesn't add up, or want to suggest a new calculator? We love feedback: every correction makes the site more useful.

What can you write to us about?

• Corrections: if a calculation, a unit, or an example seems wrong, tell us which calculator and what values you used to reproduce it.
• Suggestions: missing a calculator (for pavers, wallpaper, or fertilizer, for example)? Tell us what you need to estimate.
• Usability improvements: feedback on clarity, labels, or accessibility is welcome.

Before you write

Many questions are answered on the methodology page, where we explain the formulas and the waste and rounding criteria. Remember that our tools provide guidance estimates: for important work or structural elements, always consult a professional.

Keep in mind that the calculators run entirely in your browser and we don't store the data you enter; see the privacy policy for more details.