Paint and tile calculator

Find out how much paint to buy for a room and how many tiles you need for a floor or wall. Doors, windows, number of coats and cutting waste are all taken into account.

Room length (m)

Room width (m)

Wall height (m)

Doors

Windows

Coats

Coverage (m² per litre)

Paint the ceiling too

Area to paint—

Paint needed—

A door counts as 1.8 m² and a window as 1.5 m². Use the coverage printed on your paint tin.

How to use

Choose Paint or Tiles and enter your measurements in metres. Results update as you type.

Paint: enter the room length, width and wall height, the number of doors and windows and how many coats you plan. Tick the box to include the ceiling. The coverage (m² per litre) is printed on the tin; 10 is typical for emulsion.
Tiles: enter the size of the floor or wall and the tile size in centimetres. Add a waste allowance for cuts. If you know how many tiles come in a box, enter it to get the number of boxes.
Several areas: for an L-shaped room or several walls, work out each part separately and add the results.

Frequently asked questions

How much paint do I need for a room?

Multiply the wall area by the number of coats and divide by the coverage on the tin. A 4 × 3.5 m room with 2.6 m walls has about 36 m² of wall after a door and window; two coats at 10 m² per litre need about 7 litres.

Do I really need two coats?

Usually yes. One coat can look patchy, especially when changing colour or painting fresh plaster. Dark colours over light walls, or light over dark, may need a third coat.

How many extra tiles should I buy?

Add about 10% for cuts and breakage on a simple floor, and 15% for diagonal patterns or rooms with many corners. Keeping a few spare tiles also helps with later repairs, as batches can differ in colour.

How do I calculate tiles for a floor?

Multiply the length by the width to get the floor area, then divide by the area of one tile. A 3 × 2.5 m floor is 7.5 m²; with 30 × 60 cm tiles (0.18 m² each) that is about 42 tiles, or 46 with 10% waste.