Garden & Outdoor
Turf, topsoil, gravel, decking, fencing and tarmac - the calculators for everything outside the back door.
Turf Calculator
Up to three lawn areas to turf rolls needed, plus an optional topsoil top-up.
Topsoil Calculator
Area and depth to cubic metres, tonnes and bulk bags, with presets for lawns, beds and topdressing.
Gravel Calculator
Paths, driveways and borders: area and depth to cubic metres, tonnes and bulk bags needed.
Decking Calculator
Deck size and board dimensions: board count, joist count and lengths, and screws, laid out to scale.
Fence Calculator
Run length and panel width: panels, posts, postcrete and gravel boards, gates accounted for.
Tarmac Calculator
Driveways, footpaths and car parks: length, width and depth to cubic metres and tonnes, with waste allowed for.
Building
Concrete, screed, mortar, bricks and blocks, aggregate and skip size - the core numbers for any build.
Concrete Calculator
Slabs, footings, trenches or post holes: cubic metres, 25kg bags, ready-mix to order, and ballast and cement to mix your own.
Screed Calculator
Cubic metres, sharp sand and cement bags for a 4:1 mix, with bonded, unbonded and floating depth guides.
Mortar Calculator
Sand and cement from a brick or block count, or from wall area, with mix ratio and bag quantities.
Brick and Block Calculator
Wall length and height, single or double skin: brick or block count with wastage, plus the sand and cement for the mortar.
Aggregate Calculator
Gravel, sharp sand, topsoil or hardcore: area and depth to tonnes, bulk bags and 25kg bags.
Skip Size Calculator
Waste dimensions to cubic yards and the smallest standard skip that fits it.
Decorating & Interior
Paint, wallpaper, tiles, plasterboard and loft insulation - working out exactly how much to buy before you start.
Paint Calculator
Wall lengths and height, doors and windows deducted: litres needed and how many 1L, 2.5L or 5L tins to buy.
Wallpaper Calculator
Room perimeter, height and pattern repeat to the number of standard rolls to buy.
Tile Calculator
Area or wall dimensions with openings taken off: tile count, boxes, adhesive and grout using the standard grout formula.
Plasterboard Calculator
Wall and ceiling area to board count, screws, joint tape and jointing compound.
Loft Insulation Calculator
Loft area, existing and target depth: rolls needed for the top-up.
Guides
Explainers and worked examples to go with the calculators above, for when you want the reasoning as well as the number.
How Much Topsoil for Turf?
Depth, tonnes and bulk bags explained with a worked example, plus links to the turf and topsoil calculators.
How Many Bricks per m2?
60 bricks per m2 for a half-brick wall, 120 for double skin, with the maths shown and a worked example.
How Much Does a Skip Cost?
What drives the price - size, location, permits, duration, waste type - plus cheaper alternatives worth a look.
How Much Concrete Do I Need?
Volume for a slab, base or post hole, bags versus ready-mix and typical depths, with a worked example.
About DIYCalcs
Every tool on this site works from fixed geometry and clearly labelled standard conventions, UK brick sizes, joint widths, bulk densities, so the answer you get is a real answer, not a guess. Where a real-world figure genuinely varies, like bulk density or paint coverage, you can edit the default to match the product you're actually buying, and the article on each page explains the typical range.
No accounts, no data collection beyond standard analytics, and every calculation runs in your browser. If a tool you need is missing, or a result looks wrong, get in touch through the contact page.