Tile Calculator for Floors and Walls
Get the number of tiles and boxes for a room floor or bathroom walls, with skirting, wastage and the cost of tiles and laying.
How the tile calculation is done
Tiles are bought in boxes, so the calculator goes from the room size to the number of boxes in five steps.
- Area. For a floor: length x width. For walls (dado): the room perimeter, 2 x (length + width), x the height up to which you tile.
- Skirting (floor only). The perimeter x the skirting height. A 4 inch skirting adds a third of a sq ft for every running foot of wall.
- Deductions. Subtract doors, windows and anything fixed that will not be tiled under, such as a kitchen platform on the wall or a built-in unit on the floor.
- Number of tiles. Net area / area of one tile, plus wastage, rounded up. One 600 x 600 mm tile is 0.36 sq m, which is 3.875 sq ft.
- Boxes. Tiles / tiles per box, rounded up to a full box. The area bought is boxes x tiles per box x area of one tile, and the tile cost is worked out on that area, because you pay for full boxes.
Laying labour is worked out on the net area at the rate per sq ft you enter.
Worked example (default inputs)
A floor 12 ft x 10 ft, 600 x 600 mm tiles, 4 tiles per box, 10% wastage, 4 inch skirting, tiles at Rs 55 per sq ft and laying at Rs 25 per sq ft.
- Floor area: 12 x 10 = 120 sq ft.
- Skirting: 2 x (12 + 10) = 44 running ft x 4/12 ft = 14.7 sq ft.
- Net area: 134.7 sq ft.
- Tiles: 134.7 / 3.875 = 34.8, plus 10% = 38.2, so 39 tiles.
- Boxes: 39 / 4 = 9.75, so 10 boxes (40 tiles, 155 sq ft).
- Cost: 155 x Rs 55 = Rs 8,525 for tiles, 134.7 x Rs 25 = Rs 3,367 for laying, total about Rs 11,892.
For bathroom walls: a toilet 8 ft x 5 ft tiled 7 ft high has 2 x 13 x 7 = 182 sq ft of wall. Take off 14 sq ft for the door and you tile 168 sq ft. With 300 x 450 mm tiles (1.45 sq ft each), 10% wastage and 6 tiles per box, that is 128 tiles, or 22 boxes.
Tile sizes and what one tile covers
| Tile size | One tile covers | Tiles per 100 sq ft (no wastage) | Used for |
|---|---|---|---|
| 300 x 300 mm | 0.97 sq ft | 104 | Bathroom floors, balconies, terraces |
| 300 x 450 mm | 1.45 sq ft | 69 | Bathroom and kitchen walls |
| 300 x 600 mm | 1.94 sq ft | 52 | Walls, elevation, some floors |
| 600 x 600 mm | 3.88 sq ft | 26 | Room floors (vitrified) |
| 800 x 800 mm | 6.89 sq ft | 15 | Large rooms and halls |
| 600 x 1200 mm | 7.75 sq ft | 13 | Large floors, feature walls |
The number of tiles in a box is printed on the box with the area it covers. It changes with the brand, the tile thickness and the size, so the figure filled in for each size here is only a common pack. Always type the number from your box.
How much wastage to allow
- 5 to 7% for a plain rectangular room with large tiles laid straight.
- 10% for most rooms with a few cuts, a door and skirting. This is the default.
- 12 to 15% for diagonal laying, small rooms with many corners, patterns, or tiles with a design that must match.
Keep a few spare tiles from the same batch after the job. A broken tile later is hard to match, because shade and size can vary from batch to batch.
Common mistakes when estimating tiles
- Not buying in full boxes. The supplier sells boxes, not tiles. Work out the boxes before you compare prices.
- Mixing batches. Order all the tiles for one area together. Check that the batch or shade number on every box is the same.
- Forgetting skirting and steps. Skirting, door sills and stair risers add area that is easy to miss.
- Counting the door in the skirting. The calculator runs skirting round the full perimeter. If you have a wide opening, deduct its width x skirting height in the deduction box.
- No slope in wet areas. Bathroom and balcony floors need a slope to the drain, which means more cutting. Allow a little more wastage there.
- Price per box vs price per sq ft. Shops quote both. Price per sq ft = box price / sq ft per box. Compare on the same basis.
Tiles in the finishing budget
Tiling sits with paint and plaster in the finishing stage. Use the plaster calculator for the walls behind dado tiles, the paint calculator for the walls above them, and the house construction cost calculator for the full budget. A BOQ in Excel with one line per room keeps the tile quantities in one place.
In the Trackovo app, the site raises a material request for the tiles, the office approves and orders them, and the delivery is recorded with a photo of the boxes and the bill, so the stock of each tile at each site is known. See material management. Tiling work given on a per sq ft rate can be recorded in the measurement book and settled with the contractor; see labour management.
Common questions
How many 2 x 2 tiles are needed for a 10 x 12 room?
The floor is 120 sq ft and one 600 x 600 mm (2 x 2 ft) tile covers 3.875 sq ft, so you need 31 tiles without wastage, or 35 with 10% wastage. Add skirting if you want it: with 4 inch skirting the total is 39 tiles.
How many tiles are there in a box?
It depends on the brand and the tile. Large floor tiles such as 600 x 600 mm often come 4 to a box and 800 x 800 mm 3 to a box, but this varies. The box label gives the number of tiles and the area covered; use that figure.
How much tile wastage should I take?
10% is a safe figure for most rooms. Use 5 to 7% for large plain rooms with straight laying, and 12 to 15% for diagonal laying, patterns or small rooms with many cuts.
How do I calculate tiles for bathroom walls?
Multiply the room perimeter by the height you tile, then subtract the door and any window. A toilet 8 ft x 5 ft tiled to 7 ft has 182 sq ft of wall, or 168 sq ft after a 14 sq ft door. Divide by the area of one tile and add wastage.
Does the calculator include tile adhesive or grout?
No. Adhesive and grout coverage depend on the product and the bed thickness, so check the bag. If you lay tiles on cement mortar, estimate the mortar like plaster of the bed thickness.
Request the boxes from these numbers and check the delivery against the area tiled: track material and labour in Trackovo. Trackovo is a construction site management app with material, labour attendance, DPR and payments, with a 14-day free trial.
