---
title: "Tile calculator UK: walls or floor, in boxes | BuildBatch"
description: "How many boxes of tiles for a room's walls, a splashback or a floor? From the area, the extra for cuts and the box, with adhesive and grout. Working shown."
url: https://buildbatch.co.uk/tile-calculator/
---

# Tile calculator

Tiles, adhesive and grout, walls or floor.

An example room

## Tiling the walls of a 2.4 × 1.8 m room, to the ceiling, 1 door, 1 window, in 300 × 600 mm tiles

- **Tiles**: 117 tiles. 20.9 m² with 15% for cuts
- **Adhesive**: 5 × 20 kg. 95.6 kg needed4.4 kg left over
- **Grout**: 1 × 5 kg. 2.5 kg needed2.5 kg left over

Adhesive: with 80 kg you would be 15.6 kg short.

Built with AI tools; not yet checked by a tradesperson.

A 2.4 m ceiling, one standard door and one standard window are counted until you change them.

How many boxes of tiles a room's walls or floor take, from the area to tile, the extra for cuts and what one box covers.

Want a figure before you measure? See [how many wall tiles a bathroom takes, by room size](https://buildbatch.co.uk/examples/how-many-wall-tiles-for-a-bathroom-by-room-size/).

Tiling a floor? Choose “Floor tiles” among the jobs under the answer: this page counts it too.

**Having it done, wall tiling:** labour only, £20 to £58 per m². These are published UK figures, each its publisher's own, and not a quote: [every figure, its source and the sum for a room: wall tiling](https://buildbatch.co.uk/costs/tiling-a-bathroom/).

**How the number is worked out, a worked example and questions**

## How the number is worked out

1. **Measure what you tile.** For walls, the distance round the room and the height the tiles go up to; to the ceiling, that is the room's height. For a splashback, a shower's walls or one wall, choose “One wall” and give the width to tile. For a floor, its length times its width; a room that is not a rectangle can be drawn.
2. **Take off the doors.** On walls each comes off up to the tiled height: its width times the lower of its height and the tiled height. Windows come off only when the tiles go to the ceiling, and then their reveals are added: the edge round the window times the reveal's depth, 150 mm unless you enter it (an example figure). With one wall chosen, nothing is taken off. Nothing comes off a floor.
3. **Add the extra for cuts.** The planner starts at 10% for a straight lay or a brick bond, and 15% for a diagonal or a herringbone lay or for a tile of 600 mm or more in a room under 5 m², on walls: the figures published tiling guides give. On a floor it starts at 10%, a labelled example. Change it if the tile's fitting guide says more.
4. **Count the boxes.** The area with the extra, divided by what one box covers, rounded up to whole boxes, even when the sum is only just over a whole number. Until you give yours, a box that covers 1 m², with 10% extra for cuts: labelled examples, not a product.
5. **Count the bags.** The adhesive and grout are counted for the area without the extra, from typical figures named on each line: the grout by Norcros Adhesives' rule, and the adhesive from the trowel's notch, which follows the tile's size. Until you give the tile's size they are counted for an example tile, 300 × 600 mm on walls and 600 × 600 mm on a floor. The bag you buy says what it covers: check it against the line.

Tiled part of the way up every wall, the planner asks whether the wall above the tiles is being painted. Answer yes and it is on the same list: a “Wall paint, above the tiles” line, worked out as the paint is with the strip's height as the wall's height (a door loses its part above the tiles), at the planner's typical paint figures, with the sugar soap, filler, caulk, masking tape, dust sheets, roller, tray and brush that painting takes. Until then the list is the tiling alone. With one wall chosen there is no paint line, as the walls beside them are not known. The labour figures further down are for the tiling only.

For a floor, the list then adds what a tiled floor needs besides the tiles. What the tiles go onto comes from your answer about the floor: tile backer board or overlay ply on a timber floor, and a flat, dry floor to tile on for any other. Then tile spacers or levelling clips, sanitary silicone sealant for the edge of the floor, a threshold or door bar for each doorway, the tiling tools, and knee pads, gloves, safety glasses and a dust mask. Each is something to buy or something still to decide; a flat, dry floor is under “Before you start”, as it is the state of the floor and not a thing to buy. No underlay or damp-proof membrane is listed, because tiles are stuck down and not floated.

## A worked example

A room 3 m by 2 m and 2.4 m high, with one door 0.8 m wide and 2 m high. Boxes cover 1 m² and the extra for cuts is 10%. These are example figures, not a product.

**The same room, tiled to 1.2 m and to the ceiling**

| Working | Tiled to 1.2 m | Tiled to the ceiling |
| --- | --- | --- |
| Distance round the room | 10 m | 10 m |
| Height tiled | 1.2 m | 2.4 m |
| Wall area | 12 m² | 24 m² |
| Less the door | 0.96 m² | 1.6 m² |
| Area to tile | 11.04 m² | 22.4 m² |
| With 10% for cuts | 12.144 m² | 24.64 m² |
| Boxes to buy | **13** | **25** |
| Left over | 0.856 m² | 0.36 m² |
| Wall above the tiles, and its paint, if you paint it | 11.36 m²: 1 × 2.5 L tin | None |

The planner counts boxes by area. The box's label says how many tiles it holds, so multiply the boxes by that number to count the tiles. Copy the coverage from your own box: it changes the answer.

A floor: a room 4.2 m by 3.6 m with a tiled floor, with 10% added for cuts. One box covers 1.44 m² and the other covers 2 m². These are example figures, not a product.

**The same floor in two box sizes**

| Working | 1.44 m² boxes | 2 m² boxes |
| --- | --- | --- |
| Floor area | 15.12 m² | 15.12 m² |
| With 10% for cuts | 16.632 m² | 16.632 m² |
| Boxes to buy | **12 boxes** | **9 boxes** |
| Tiles in those boxes | 17.28 m² | 18 m² |
| Left over | 0.648 m² | 1.368 m² |

The box size changes the count: 12 boxes of one and 9 boxes of the other for the same floor. The adhesive and grout are counted for the floor's 15.12 m², without the allowance.

For a 600 × 600 mm tile the planner counts them from typical figures: 6 bags of 20 kg adhesive with a 10 mm notched trowel (about 7 kg a square metre, a typical figure from five makers' sheets for a floor tile over 300 mm and up to 600 mm on its long side), and 1 bag of 5 kg grout for an example 3 mm joint and 10 mm tile, by Norcros Adhesives' rule. At that rate a 20 kg bag of adhesive covers about 2.9 m²: the bags' own labels state 4 to 5 m², for a thin 3 mm bed on a flat floor. The figure on your own bag still comes first: by hand, an adhesive that covers 4 m² a bag and a grout that covers 6 m² a bag are 4 bags and 3 bags for this floor.

[Work it out for your room](https://buildbatch.co.uk/start/#v=1&job=paint&walls=tiles&ceiling=none&trim=none&units=m&length=3&width=2&height=2.4&door=0.762x1.981&window=0.9x1.2&surface=sound&subfloor=unsure&ground=unsure&fitting=unsure&walltiles=quick&walltiles.tilew=300&walltiles.tileh=600&end=18), starting from the example room's sizes.

## Mistakes that cost a box

- **Using the room's height when the tiles stop lower.** The tiled height sets the area. In the example it is 13 boxes to 1.2 m and 25 to the ceiling.
- **Taking a window off when the tiles stop below it.** A window that starts above the tiles takes nothing off them. The planner takes windows off only when the tiles go to the ceiling.
- **Leaving out the extra for cuts.** In the floor example the bare area divided by 1.44 m² says 11 boxes; the room needs 12 boxes. A diagonal or herringbone layout, and large tiles in a small room, lose more.
- **Working from the tile's size.** The size of one tile does not say how many are in the box. Use the square metres printed on the box you are buying.
- **Buying boxes from different batches.** The shade can differ between batches. The box shows the batch.

## Questions

**How many boxes of floor tiles for a 4.2 m by 3.6 m room?**

With boxes that cover 1.44 m² and 10% extra for cuts, 12 boxes. The floor is 15.12 m², which is 16.632 m² with the extra. With boxes that cover 2 m² it is 9 boxes.

**Do I take off the doors and windows?**

Doors come off up to the height you tile to. Windows come off only when the tiles go to the ceiling, because below that the planner does not know where the sill is. Tiled to the ceiling, a window's reveals are tiled too, and are added. With one wall chosen, nothing is taken off, because which wall each opening is on is not known.

**How many tiles for a splashback?**

Choose “One wall” and give the splashback's length, usually the worktop's, with the height it goes up to. A splashback 3 m long and 0.6 m high is 1.8 m²; with 10% for cuts and boxes that cover 1 m², that is 2 boxes, where the whole room would have been counted otherwise. The adhesive, grout and trim are counted for the same length.

**How much extra do I add for cuts?**

The planner starts at 10% for tiles laid straight or in a brick bond and 15% for a diagonal or a herringbone lay, typical figures from published tiling guides; one of them gives a brick bond 15% too. Answer “Laid in which pattern?” and the extra follows it. On a floor the planner starts at 10%, a labelled example and not a standard. The tile's fitting guide comes first: change the figure to match.

**Does it count adhesive and grout?**

Yes. Give the tile's size where the room is measured, and the planner counts both from typical figures, each named on its line: the grout from the joint's volume, by the rule Norcros Adhesives publishes on its grout data sheet, and the adhesive from the notched trowel, which follows the tile's long side and where it goes. On a wall the planner follows BuildBatch's own rule, which is under review: a tile up to 600 mm on its long side is counted at a 6 mm notch and 5.25 kg a square metre, and a larger one at a 12 mm notch and 10.5 kg. The 600 mm limit, and which rate a wall tile takes, are BuildBatch's choice; the two rates are the middle of Sika's Supracoat figures for 30 cm tiles and for large tiles. The makers' sheets read give a wall tile over 300 × 300 mm a deeper notch on a solid bed: BAL's Rapid-Flex One a 10 mm notch (its 6 mm notch on an inside wall is for tiles up to 300 × 300 mm), and Mapei's Mapeker Rapid-Set Flex 8 to 10 mm at 4 to 5 kg a square metre, with the backs buttered. On a floor: 5.25 kg with the 6 mm notch for a tile up to 300 mm and 10.5 kg with the 12 mm notch for one over 600 mm, both by Sika's data sheet, and about 7 kg with a 10 mm notch for a tile in between, a typical figure from makers' sheets (BAL, Mapei, ARDEX, Instarmac and Bostik). They come in 5 kg bags of grout and 20 kg bags of adhesive. A joint or tile thickness left blank is an example, and the line says so; so is the tile counted until you give yours, 300 × 600 mm on walls and 600 × 600 mm on a floor. The bag you buy says what it covers: check it against the line.

**What do the tiles go onto?**

The list asks what is under the floor. A timber floor flexes, and tiles crack on a floor that moves, so the list has tile backer board or overlay ply to buy. On concrete or screed, and until you answer, it has a flat, dry floor to tile on under “Before you start”: that is the state the floor must be in, not a thing to buy. The adhesive's and the board's instructions decide.

## Related guides

- [How many tiles do I need for a floor or a wall?](https://buildbatch.co.uk/guides/how-many-tiles-do-i-need/)
- [Floor tile box coverage: three sizes worked out](https://buildbatch.co.uk/guides/floor-tile-box-coverage-worked-out/)
- [How much tile adhesive and grout do I need?](https://buildbatch.co.uk/guides/how-much-tile-adhesive-and-grout-do-i-need/)

Everything is worked out in your browser, and BuildBatch never sends the figures you type unless you sign in to an account and save a project. BuildBatch counts which tools are used, without a cookie. Not yet checked by a tradesperson: the box's own label comes first. [How the estimates are worked out](https://buildbatch.co.uk/how-estimates-work/).