Material Maths

How much do I need? Free UK DIY & Garden Materials Calculators

Measure once. Buy the right amount. Real UK bag sizes, honest cost estimates and a shopping list you can take straight to the builder's merchant.

GravelTopsoilGrass seedShed baseHot tub base

Plan a whole project

One form works out every material for the whole job — not just one bag at a time.

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Build a patio planner

Slabs, sub-base, sand, jointing and edging in one go.

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Browse by category

Garden & LandscapingGravel, topsoil, bark, turf, decking and raised beds.Driveways & PavingSlabs, block paving, sub-base and sand.Building & MasonryConcrete, bricks, blocks, mortar, plasterboard and render.DecoratingPaint, wallpaper, skirting and coving.Flooring & TilingTiles, grout, laminate, vinyl and underlay.Plan & BudgetCompare DIY with hiring a pro, and check what fits in your car.

Most popular calculators

Gravel & chippings calculatorTonnes and bulk bags for paths, borders and driveways.Topsoil calculatorTonnes and bags for lawns, beds and borders.Grass seed & lawn feed calculatorSeed, feed and packs for a new lawn, overseeding or patching.Shed base calculatorConcrete, slab, timber or grid bases for any shed size.Hot tub base calculatorFilled weight, floor loading and the right base to build.Concrete calculatorReady-mix, bags or mix-your-own for slabs, footings and posts.Stud wall calculatorTimber, plasterboard, screws, skim and insulation.Paint calculatorLitres and tins for walls, ceilings and woodwork.Tile calculatorTiles, boxes, adhesive and grout for floors and walls.DIY vs pro cost calculatorCompare materials and your weekends against trade day rates.

Why Material Maths?

UK sizes only

215mm bricks, 850kg bulk bags, 2.5L and 5L tins, 1.83m fence panels.

Real shopping lists

Exactly what to buy, ready to copy, print or email.

Cost estimates

Editable UK prices so you know roughly what the job costs.

Free, no sign-up

No account, no email, no paywall. Just answers.

Latest guides

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How Much Carpet Do I Need? Measuring for Carpet

Measure for UK roll widths, seams, underlay, gripper and stairs.

How Much Loft Insulation Do I Need?

Understand the 270mm recommendation, top-ups, roll coverage and safe fitting.

What Size Radiator Do I Need? BTU Explained

Convert BTUs and watts and account for room size, glazing and insulation.