The math is shown
Every calculator publishes its formula and a worked example, so you can check the result before you spend money on materials.
Free renovation calculators
Measure once.
Measure once.
Buy the right amount.
Materials calculators for real renovation jobs - tiles, paint, concrete, flooring and more. Every tool shows its formula, handles wastage properly, and works in feet or metres.
Pick a tool
All calculators
17 material calculators, each with its formula shown and wastage handled. More on the way.
Walls, floors & interior
Finish a room - tiling, flooring, painting, papering and boarding.
01
Tile Calculator
How many tiles and boxes to buy for a floor or wall, with wastage built in.
Open calculator →02Paint Calculator
Litres or gallons of paint for walls and ceilings, with coats and coverage built in.
Open calculator →03Wallpaper Calculator
How many rolls of wallpaper to buy for a room, with the pattern repeat built in.
Open calculator →04Flooring Calculator
Planks and boxes of laminate, vinyl or hardwood flooring, with layout wastage.
Open calculator →05Stud Wall Calculator
Studs, plate/track and plasterboard sheets for a partition wall.
Open calculator →06Drywall Calculator
Sheets, screws, joint compound and tape to board and finish a room.
Open calculator →Outdoor & structures
Build outside - decks, fences, patios, steps and concrete.
07
Concrete Calculator
Cubic volume and bags of concrete for slabs, footings, pads and posts.
Open calculator →08Concrete Mix Ratio Calculator
Cement, sand, aggregate and water for any concrete mix ratio.
Open calculator →09Decking Calculator
Deck boards, total board run and joists for a deck of any size.
Open calculator →10Paver Calculator
Pavers, gravel sub-base and bedding sand for a patio, path or driveway.
Open calculator →11Fence Calculator
Posts, rails, pickets and post-mix concrete for a fence of any length.
Open calculator →12Stair Calculator
Risers, treads, rise, run, stringer length and pitch - checked against your country's stair code.
Open calculator →13Roof Pitch & Rafter Length Calculator
Common rafter length, roof angle, slope and rise from any pitch.
Open calculator →Landscaping & soil
Fill and cover by volume - mulch, gravel, topsoil and garden beds.
14
Mulch Calculator
Volume and bags to cover beds with mulch or bark at any depth.
Open calculator →15Gravel Calculator
Volume and bags of gravel for driveways, paths and drainage at any depth.
Open calculator →16Topsoil Calculator
Volume, litres and bags of topsoil for lawns, turf and garden beds.
Open calculator →17Raised Bed Soil Calculator
Soil volume and bags to fill one or more raised garden beds, with mix ratios.
Open calculator →
Advanced mode · built into every calculator
Try it on the tile calculator
Override the presets. Match your real job.
It's not a separate tool - every calculator already lets you go past the defaults. Set a custom waste percentage for your exact layout, and enter your own tile, plank, board, box and tin sizes, so the count reflects the materials you'll actually buy.
- Custom waste %
- Tile & plank sizes
- Box & tin sizes
- Per-layout allowances
Why these tools
Built like a takeoff sheet, not a toy
The same numbers an estimator would run by hand - transparent, unit-aware and rounded the way a real order is placed.
// TILE.FORMULA
area = 5.0 × 4.0 = 20.0 m²
per_tile = 0.6 × 0.6 = 0.36 m²
tiles = ⌈ 20 ÷ 0.36 × 1.10 ⌉
→ 61 tiles
Feet or metres, correctly
All calculations run in exact metric units internally and convert at the display layer - switching units never changes the answer.
Wastage built in, honestly
Layout-specific allowances (grid, offset, herringbone) instead of a vague “add some extra” - so you buy enough, once.