Building & Repair
Building & Repair tools on UniTools: how much wallpaper and flooring, concrete and brick quantities and more.
This section answers the one question that comes before every trip to the merchant: how much to buy. Wallpaper in rolls, flooring in packs, tile in boxes, mix in bags — the answer arrives in the units the material is actually sold in.
The details people get wrong are built in: a pattern repeat lengthens every strip of wallpaper, the grout joint is part of a tile's effective size, roof pitch enlarges the area, and a fence always has one more post than it has bays.
Tools in this category
Wall Area Calculator
Perimeter, wall area with windows and doors taken out, plus floor and ceiling area. The number every decorating estimate starts from.
Wallpaper Calculator
How many rolls a room needs, allowing for pattern repeat, ceiling height and openings, plus how much offcut ends up in the bin.
Laminate Flooring Calculator
Packs of laminate including a cutting allowance, how much area is left over, and how many rolls of underlay to buy.
Tile Calculator
Tile count allowing for joint width, how many boxes that is, and how much adhesive and grout the job will take.
Paint Calculator
How much paint a given number of coats will take, how many tins that is, and how much primer to add.
Concrete Calculator
Concrete volume for a slab, strip footing or piles, broken down into cement, sand, gravel and water for the grade you choose.
Brick Calculator
Brick count from wall area and thickness, allowing for brick type, joint width and breakage, plus the mortar volume.
Screed Calculator
Mix volume, number of bags, water needed and how long the screed will take to dry at the thickness you choose.
Drywall Calculator
Board count including cutting waste, metres of framing, screws, jointing compound and scrim tape.
Insulation Calculator
Insulation volume, number of packs, mass, and the thermal resistance the finished layer will deliver.
Roofing Calculator
Roof area allowing for pitch and overhangs, the number of sheets needed and the ridge length.
Pipe Volume Calculator
How much water a pipe holds, litres per metre, external surface area and the mass of the pipe itself.
Lumber Calculator
Timber volume in cubic metres, how many boards fit in a cube, total area covered, mass and cost.
Fence Calculator
Posts, bays, rails and sheets for a fence of any length, plus concrete for setting the posts.
Square Footage Calculator
Area of a rectangle, triangle or circle given straight away in square metres, square feet, square yards, hectares and acres.
Related categories
FAQs
How much should I allow for cutting?+
Five percent laying straight, seven staggered, ten to fifteen diagonally. Add another five in a room with bays or alcoves.
Should I deduct windows and doors?+
For wallpaper, paint and tile, always. For plaster and primer usually not, since the reveals need finishing anyway.
How accurate are these estimates?+
They give quantities with a normal allowance, which is enough for a quote. Tile layout and sheet cutting still have to be worked out on site.
What about an irregular room?+
Split it into rectangles, calculate each and add them. For the perimeter, simply measure every wall and add the lengths.