About Material Maths
Material Maths exists for one reason: far too many people either run out of materials halfway through a job, or end up with three spare bulk bags rotting behind the shed.
Who it's for
Homeowners and DIYers in the UK doing real jobs — laying a patio, gravelling a drive, painting a bedroom, tiling a bathroom, putting up a fence. If you have ever stood in a builder's merchant wondering whether one bulk bag is enough, this site is for you.
Why it's different
- UK sizes only. 215 × 102.5 × 65mm bricks, 440 × 215mm blocks, 25kg cement bags, 850kg bulk bags, 2.5L and 5L tins, 10.05m × 0.52m wallpaper rolls and 1.83m fence panels.
- Shopping lists, not just numbers. Every calculator tells you exactly what to buy, in the units your merchant sells.
- Cost estimates with editable prices. Put in your own supplier's figures and get a realistic total before you commit.
- Whole-project planners. A patio is not just slabs — it's sub-base, bedding, jointing compound, membrane and edging. Our planners work out the lot.
- Free, with no sign-up. No account, no email address, no paywall. The site is funded by advertising.
How we work out the numbers
Every calculator uses standard UK trade densities, coverage rates and product sizes, all shown on the page and all editable in the Advanced settings panel. We explain the formula in plain English underneath each tool, so you can check the maths yourself rather than trusting a black box.
A note on estimates
Results are estimates. Ground conditions, compaction, wastage, surface porosity and supplier tolerances all move the numbers. Always confirm quantities with your supplier or builder before ordering, and check anything structural with a qualified professional.
Spotted something wrong, or want a calculator we haven't built yet? Email hello@materialmaths.co.uk or use the contact form.