Quick answer
To find how many tiles you need, divide the area you are tiling by the area one tile covers, then add a waste allowance and round up to full boxes. Work in the same units: a 12 in by 12 in tile covers 1 square foot, so a 10 ft by 8 ft wall of 80 square feet needs 80 tiles, plus 10% for cuts and breakages, which is 88 tiles, or 9 boxes if a box holds 10.
How to use the tile calculator
- Choose how you want to enter the area: length and width, or total square footage.
- Enter your tile size, or pick a common size from the list.
- Set a waste allowance. Use 10% for a straight layout and 15% for diagonal or herringbone.
- Add tiles per box and a price if you want boxes and total cost.
- Read the number of tiles, boxes to buy and the cost.
- The imperial and metric toggle covers both the room and the tile size.
Worked example
A bathroom wall is 10 ft wide and 8 ft high, so the area is 80 square feet. The tiles are 12 in by 12 in, which is 1 square foot each.
- 1.Tiles before waste: 80 / 1 = 80 tiles
- 2.Add 10% waste: 80 x 1.10 = 88 tiles
- 3.Boxes, if a box holds 10: 88 / 10 = 8.8, rounded up to 9 boxes
You order 9 boxes, which is 90 tiles, leaving a small number of spares for future repairs.
When to use this
The formula
Two steps give the tile count:
Area / tile size = tiles, then tiles x (1 + waste) rounded up = tiles to buy.
Both the area and the tile size are converted to the same unit first. One tile covers its width times its height, so a 12 in by 12 in tile covers 144 square inches, or 1 square foot. Dividing the total area by that gives the tile count before waste.
Tiles needed per 100 square feet
Before waste, by tile size. Multiply by your area in hundreds of square feet, then add waste.
| Tile size | Area per tile | Tiles per 100 sq ft |
|---|---|---|
| 3 in x 6 in (subway) | 0.125 sq ft | 800 |
| 4 in x 4 in | 0.11 sq ft | 900 |
| 6 in x 6 in | 0.25 sq ft | 400 |
| 12 in x 12 in | 1 sq ft | 100 |
| 12 in x 24 in | 2 sq ft | 50 |
| 18 in x 18 in | 2.25 sq ft | 44 |
| 24 in x 24 in | 4 sq ft | 25 |
Swipe sideways to see all columns
Floors, walls and odd shapes
For an L-shaped room or a wall with a window, split the surface into rectangles, work out each one, and add them together. Subtract large openings such as a window or a door. Buy from the same batch so the shade matches, and keep a few spare tiles after the job, since the same colour can be hard to find later.
Common mistakes
Frequently asked questions
Divide the area you are tiling by the area one tile covers, then add 10 to 15% for waste and round up to full boxes. For 80 square feet with 1 square foot tiles that is about 88 tiles after 10% waste.
Measure the length and width of the surface in feet and multiply them. A 10 ft by 8 ft wall is 80 square feet. For an odd shape, split it into rectangles, work out each one and add them up.
Add 10% for a straight layout and 15% for diagonal or patterned layouts. Keep a few spare tiles after the job for future repairs, since the same shade may be hard to match later.
Treat each wall as its own rectangle, work out the tiles for each, then add them. Subtract large openings such as a window. The calculator handles one surface at a time, so add the results together for a full shower.
Enter the price per box or per tile and the calculator multiplies it by the number you need to buy. This is the material cost only. Installation labour, adhesive and grout are separate.
References. The formulas and figures here follow standard construction references. See our Methodology for how we check them. Area maths use standard geometry.
Related calculators
Estimates only. Check supplier specs and local codes before you order or build.