Floor / Tile Area Calculator
Estimate floor area and the number of tiles and boxes to buy for a tiling project — accounting for grout gap, a wastage allowance and box rounding, for rectangular or L-shaped rooms in metric or imperial units.
Input
Metric enters rooms in metres and tiles in millimetres; imperial uses feet and inches.
L-shape adds a second rectangle (the extension) to the total floor area.
Main room length (metres in metric, feet in imperial).
Main room width (metres in metric, feet in imperial).
Single tile length (millimetres in metric, inches in imperial).
Single tile width (millimetres in metric, inches in imperial).
Spacing between tiles (millimetres in metric, inches in imperial).
Extra tiles for cuts, breakage and future repairs (5-10% for a straight layout, 15-20% for diagonal or herringbone).
How many tiles come in one box, used to round the purchase up to whole boxes.
Output
| Metric | Value |
|---|---|
| No data yet | |
One-line overview of floor area, tiles (with wastage) and boxes to buy.
Guides
The Floor / Tile Area Calculator estimates how many tiles and boxes you need for a flooring project. Enter your room and tile dimensions and it works out the total floor area, the number of tiles required (with and without a wastage allowance), the count of cut tiles, and how many boxes to buy — rounded up to whole boxes so your order is realistic. It handles rectangular and L-shaped rooms in either metric or imperial units.
How to use it
- Pick your unit system — metric (rooms in metres, tiles in millimetres) or imperial (rooms in feet, tiles in inches).
- Choose the room shape. For an L-shape, add the extension's length and width; they are added to the main rectangle to give the total floor area.
- Enter the room dimensions, then the single tile length and width and the grout gap between tiles.
- Set a wastage percentage for cuts, breakage and future repairs, and the number of tiles per box.
Results update instantly. The table shows floor area, effective tile area, tiles needed, cut/waste tiles, total coverage from your purchase and the number of boxes to buy. A one-line summary is provided for quick copying.
How is the tile count calculated?
Each tile is treated as occupying an effective grid cell of (tile length + grout) x (tile width + grout). Dividing the total floor area by this cell area gives the base tile count. The wastage percentage is then applied and the result is rounded up, and boxes are rounded up from there. Including the grout joint gives a more accurate figure than dividing by the bare tile size alone.
How much wastage should I add?
A common rule of thumb is 5-10% for a straight (grid) layout and 15-20% for diagonal or herringbone patterns, where more tiles are cut. Larger rooms and simpler shapes trend toward the lower end. Keeping a few spare tiles is wise for future repairs, since dye lots change between production runs.
Does it account for the grout gap?
Yes. The grout gap widens the space each tile covers, so a wider joint slightly reduces the number of tiles needed. Set the grout gap to 0 if you are laying rectified tiles with no visible joint.
Can I use it for walls?
Yes — the math is identical for any flat rectangular surface. Enter the wall's height and width in place of the room length and width. For an area with two wall sections, use the L-shape option to add them together.
Is my data private?
Completely. Every calculation runs entirely in your browser. Nothing you type is uploaded, stored or sent to a server, so you can estimate as many rooms as you like in total privacy.