How much tile, paint or flooring do you need?
Calculators for finishing a room: enter your measurements and get the number to put in the cart, with the waste allowance and the math shown.
ft² floor + 10% for cuts and spares
Need several areas, a diagonal layout or boxes? Use the floor tile calculator.
Calculators by project
Tile calculators
Floor tile, backsplash and shower walls: tiles, boxes and waste by layout.
Paint calculators
Gallons for walls, ceilings, trim and exteriors, by coats and coverage.
Drywall calculators
Sheets, mud, tape and screws for walls and ceilings.
Flooring calculators
Laminate, vinyl plank, hardwood and carpet, by the box or the yard.
Wallpaper calculator
Rolls for a room or an accent wall, with pattern repeat.
Baseboard & trim
Linear feet and pieces of baseboard, casing and crown.
Why the extra matters
Tile, wallpaper and flooring are made in batches, and the next batch rarely matches exactly. Buying a few percent extra up front means cuts, breakage and future repairs all come from the same lot. Typical allowances:
| Layout | Typical extra | 12×12 in tiles for a 120 ft² room |
|---|---|---|
| Straight | 10% | 132 |
| Brick / offset | 10% | 132 |
| Diagonal | 15% | 138 |
| Herringbone | 15% | 138 |
How we calculate
Every calculator follows the same steps and shows them: measure the area, divide by what one unit covers (a tile, a gallon, a sheet), add the waste allowance and round up to whole units and whole boxes. Details and sources are on the methodology page.
Results are planning estimates. Check the coverage printed on your product (square feet per box, per gallon or per sheet) and enter it where the calculator asks; manufacturers differ, and the label wins.
12 ft × 10 ft = 120 ft² · 120 × 1.10 = 132 ft² ÷ 1 ft² per 12×12 tile = 132 tiles