Free tools
Renovation calculators
Quick answers for planning a renovation, with the working shown, in metric or imperial. Free, and no account needed.
Planning
- Radiator and BTU calculatorEach room's heat loss on a cold day in watts and BTU/h, and the radiator output that covers it, with a boiler or a heat pump.
- Air-con calculatorEach room's cooling load on a hot day in watts and BTU/h, the split unit size that covers it, and whether its heating would keep the room warm in winter.
- Floorplan creatorDraw your home room by room, with its walls, doors and windows, on one floor or several, and see it in 3D. Every wall shows its length and every room its area and perimeter, ready for the paint, flooring, skirting, radiator and air-con calculators. Export it as an image, or as a PDF with Premium.
Decorating
- Paint calculatorHow much paint your walls and ceilings need, in litres and tins, with doors and windows taken off.
- Wallpaper calculatorHow many rolls of wallpaper a room needs, counted drop by drop with the pattern repeat, and the paste to hang them.
- Skirting and coving calculatorHow much skirting, coving or architrave a room needs, with a cut list against the lengths it's sold in.
Flooring and tiling
- Flooring calculatorHow many packs of laminate or wood flooring, or how much carpet or vinyl off the roll, with underlay and scotia.
- Tile calculatorHow many tiles and boxes a floor or wall needs, with the joints, the cuts and the layout allowed for.
- Grout and adhesive calculatorHow much grout, tile adhesive and sealant a tiling job needs, in kilos, bags and cartridges.
Walls
- Stud wall builderPlan a stud partition in timber or metal, wall by wall with its doors and windows: studs, plates, noggins, boards and fixings, with a cut list and the wall drawn in plan, elevation and 3D.
- Brick and block wall builderPlan a brick or block wall, one leaf or a cavity wall, wall by wall with its doors and windows: bricks and blocks with their cuts, mortar as sand and cement, wall ties, insulation, DPC and a course plan, drawn in plan, elevation and 3D.
Building materials
- Concrete and screed calculatorHow much concrete for a slab, post holes or a footing you've been given the size of, in bags, ready-mix or a site mix, and sand and cement for a floor screed.
- Insulation calculatorRolls of loft insulation, or slabs and boards for walls and floors, for the thickness you want, layer by layer.
Outdoors
Conversions
Calculations we leave to professionals
Some sums decide whether a building stays up or a home stays safe. For those we explain what's involved and who to ask, and give no figures.