Article
How many tiles to buy
Before you buy tiles, calculate the piece count from area and waste. Tiles sell in boxes, and cuts need a reserve.
The tile calculator does this count. Area: floor area.
The idea in brief
Divide the floor area by one tile, add waste for cuts, and round the piece count up.
A 60 by 60 cm tile is 0.36 m². An 18 m² room needs 50 tiles with no waste. Ten percent waste makes 55, and the card reports 56. Tile width and height stay in centimeters even when the room area is in square feet.
On this page: m² means square meters. cm means centimeters. A 60 by 60 cm tile is 0.36 m², because 60 cm is 0.60 m and 0.60 × 0.60 = 0.36. Waste is a percent added to the tile count.
When this helps
| Situation | What the card shows |
|---|---|
| You count a living room first with no waste, then with waste for cuts. | The calculator divides the area by one tile, adds waste, and rounds the piece count up. |
| In the bathroom you are not tiling under the tub. | You subtract the tub opening from the area, and only then add waste. |
| You are laying tiles in a herringbone or a diagonal pattern. | Herringbone adds 10 waste points on this card, and a diagonal adds 5, because there are more cuts. |
| Tiles are sold in boxes, not as single pieces. | You round the piece count up to a full box. |
Area of one tile first
Take width and height in centimeters. 60 by 60 cm is 0.36 m². 30 by 60 cm is 0.18 m². If the box already prints area in square meters, you can enter that instead of multiplying the sides.
Then divide the floor or wall (minus recesses you leave empty) by that area. The raw count still has no waste. In a bathroom or on a diagonal that no-waste number almost never lasts.
Waste, pattern, and boxes
The card adds a waste percent, then rounds tile count up. A straight layout adds nothing on its own. A diagonal adds 5 waste points, herringbone adds 10, because there are more cuts. An 18 m² room, 60×60 cm tile, and 10% waste is 56 tiles. A 7.2 m² bath at 30×60 cm and 12% is 45 tiles.
If tiles come 6 or 8 to a box, round up to a full carton. Two years later a new lot can shift shade, so two spare tiles in a closet beat hunting the series.
A worked example
An 18 m² room
A 60 by 60 cm tile is 0.36 m². Room 18 m² and 10% waste:
- 18 / 0.36 = 50 tiles with no waste.
- Plus 10%: 55.
- Round up to 56.
In boxes of 6 that is ten cartons, not nine.
Typical numbers from the card
| Inputs | Result |
|---|---|
| The room is 18 m², the tile is 60 by 60 cm, and waste is 10%. | The result is 56 tiles. |
| The bathroom is 7.2 m², the tile is 30 by 60 cm, and waste is 12%. | The result is 45 tiles. |
| You need 56 tiles, and each box holds 6. | You buy 10 boxes, not 9. |
Typical mistakes
| Mistake | What goes wrong | How to avoid it |
|---|---|---|
| You divide the area by the tile and skip waste. | You run short of tiles for the cuts along the walls. | Add waste first, then round the piece count up. |
| You use the same waste percent for herringbone as for a straight layout. | You buy too few tiles. | On this card herringbone itself adds 10 waste points. |
| The tub stays in the area even though you are not tiling under it. | You buy extra tiles for a floor you will not see. | Enter the tub as an opening. |
| For 56 tiles you take 9 boxes of 6. | You are two tiles short. | 56 divided by 6 rounds up to 10 boxes. |
Before you buy tiles
- Area comes from a measurement or from the floor-area calculator.
- You have subtracted the openings you are not tiling.
- One-tile area comes from the sides in centimeters, or from the number on the box.
- Waste matches the layout: straight, diagonal, or herringbone.
- The tile count is rounded up.
- The box count is rounded up too.
Frequently asked questions
How many tiles for 18 m² at 60×60 cm and 10% waste?
56 tiles. One tile is 0.36 m²; 18 / 0.36 × 1.10 rounds up.
Does herringbone need more waste?
On this card herringbone adds 10 waste points, a diagonal adds 5. A straight layout only uses the percent you type.
Should I subtract the bathtub?
Yes, if you are not tiling under it. Enter that as an opening, or you buy reserve for a hidden floor.
How do I count boxes?
Tiles divided by tiles per box, always rounded up. Half a carton is rarely for sale.
Is adhesive in this result?
No. Adhesive is a separate card from coverage per square meter and bag size.
Where does 18 m² come from?
From room length and width, or from the floor-area calculator.