All calculators

21 free calculators across 8 categories — concrete, gravel, sand, topsoil, mulch, paint, wallpaper, flooring, roofing, decking, fencing, and planning costs.

Every tool page shows the formula, a worked example, and a FAQ. US and UK units are supported. Results are planning figures: confirm with a supplier or contractor before you order. For the “why” behind waste and thickness, see the guides.

Browse by category below, or use search in the header to jump straight to a tool.