Online tools for builders and self-builders.
Free calculators and converters for every job on site. Pick one, type your numbers, add the result to your quote list — done.
- No sign-up
- Saves to your clipboard
- Works on every device
- Trade-counter reviewed
All material calculators
The whole suite on one page: bricks, blocks, mortar, concrete, plaster, insulation, roofing, timber, aggregates, screed and lintels.
Open the suiteConcrete calculator
Work out the volume of ready-mix concrete you need for slabs, strip footings and columns. Built-in wastage allowance.
Calculate concretePaving calculator
Estimate slabs, MOT Type 1 sub-base and bedding sand for patios, driveways and pathways.
Calculate pavingTile calculator
Work out how many wall or floor tiles you need for any room, including a wastage allowance for cuts and breakages.
Calculate tilesMortar calculator
Estimate 25 kg cement bags and building sand for brickwork, blockwork and pointing at 1:3, 1:4, 1:5 or 1:6 mix.
Calculate mortarPlaster calculator
Estimate plaster bags, render quantity or plasterboard sheets for walls and ceilings.
Calculate plasterCoverage calculator
Estimate paint, render, primer, sealant, tile adhesive or grout quantities with manufacturer spread rates.
Calculate coverageUnit converter
Convert metres to feet, m² to ft², m³ to cubic yards, kg to tonnes and Celsius to Fahrenheit.
Convert unitsCalculator FAQs
- Are the calculators free to use?
- Yes. Every calculator and converter on this page is free. There is no sign-up and no limit on how many times you can use them.
- How accurate are the results?
- Figures are based on standard UK trade rules of thumb and manufacturer coverage rates. Always add the recommended wastage allowance and double-check critical quantities with your engineer or architect.
- Can I save or share my calculation?
- You can copy the result or add materials directly to your quote list. From there you can request a written trade price by email or phone.
- Do the calculators work on mobile?
- Yes. Every tool is responsive and works on phones, tablets and desktops, so you can estimate quantities while on site.
- What if the material I need is not listed?
- Send your take-off to the trade counter. We can price specialist materials, confirm coverage rates and turn your estimate into a delivered quote.
Need a quantity we don't calculate yet?
Send your take-off and we'll quote it directly — usually within the hour during trade hours. No call needed for a written price.