All calculators

21 free calculators across 8 categories — concrete, gravel, sand, topsoil, mulch, paint, wallpaper, flooring, roofing, decking, fencing, and planning costs. Each tool is built for the same job: turn tape-measure inputs into an order quantity you can take to a supplier.

Every tool page shows the method before the interactive calculator, then a formula, worked example, and FAQ. US (feet/inches, yards, tons) and UK (metres, cubic metres, tonnes) units are supported; switching units converts what you already typed. Cost lines are planning bands from editable national defaults — not a live quote and not a promise of what you will pay locally.

Start with a category below if you know the trade, or use search in the header for “concrete”, “paint”, or “roof”. When two contractor quotes disagree on thickness, waste, or base depth, open a guide for the context behind the number. See also how we calculate and the disclaimer.

These tools do not replace a site visit, structural design, or building-control approval. Confirm quantities before you order, especially for load-bearing slabs, roofs, and retaining work.