Our House Print

Wallpaper and paint calculator

Type the size of the room and the figures from your roll or tin. You get the number of rolls and tins, with the sum shown so you can check it.

The room

Wallpaper

Copy these from the roll's label or the product page. Rolls are not all the same size.

Paint

Filled in with the figures Dulux gives for Dulux Matt: up to 14 m² a litre, 2 coats, a 2.5 litre tin. Change them to match your tin. Checked against the Dulux Matt product page on 30 October 2026.

Fill in the room and the answer appears here.

A sheet of brown paper taped to a pale wall above a wooden sideboard.
Measure twice before the first roll is cut.

How to use it

Measure the length and width of the floor and the height of the walls, in metres. For wallpaper, copy the roll length, the roll width and the pattern repeat from the label. Rolls are not all the same size, so do not guess them. For paint, the boxes start with the figures Dulux prints for its Dulux Matt. Change them to the ones on your own tin.

A red-brick terraced house with a bay window, as a soft watercolour illustration. The House Illustration From £19.99 8 formats

One photograph of the front of the house, restyled into an illustration. The watermarked preview is free.

How the wallpaper sum works

We measure the distance round the room and divide it by the roll width to get the number of strips. Graham & Brown advises not taking off doors and windows, so the spare covers mistakes, and we follow that. Each strip is the wall height plus 10 cm for trimming, 5 cm at the top and 5 cm at the bottom. That allowance is ours.

With a pattern, each strip is rounded up to a whole number of repeats, so the pattern lines up. For an offset (half-drop) match we add half a repeat to every strip, our allowance for lining up every other one. Then we count how many whole strips fit on one roll, because a short offcut is waste, and divide. Graham & Brown also advises allowing an extra 10% for waste, so we show that figure too.

A pale painted hallway with a framed painting of a stone house hung above a radiator.
Paint first, then the pictures.

How the paint sum works

The wall area is the distance round the room times the height, less any doors and windows you type in. Add the ceiling if you tick it. Then area × coats ÷ coverage gives the litres, and the litres divided by your tin size, rounded up, gives the tins. A tin's coverage is often given as "up to", the best case, so a rough or thirsty wall can take more.

Sources

  • Graham & Brown, How to measure for wallpaper: ignore doors and windows, allow an extra 10%, the three match types. Read 30 October 2026.
  • Dulux, Dulux Matt: coverage up to 14 m² a litre, 2 coats, sold in 2.5 litre tins among others. Read 30 October 2026.

When the walls are done, the room needs something on them. A picture of your own house is a good start, and our guide to hanging it covers the rest.

Written by Craig Fearn, Our House Print. Last updated .

A few practical answers

How many rolls of wallpaper do I need?
Divide the distance round the room by the roll width to get the strips, then see how many strips of your wall height fit on one roll. For a 4 m by 3 m room, 2.4 m high, with a roll 10.05 m long and 53 cm wide and no pattern, that is 27 strips at 4 a roll: 7 rolls, or 8 with 10% spare.
Should I take off the doors and windows?
For wallpaper, Graham & Brown advises not to: the extra covers mistakes. For paint you can, by typing their area in the box.
How much paint for a room?
Area × coats ÷ coverage. The walls of a 4 m by 3 m room, 2.4 m high, are 33.6 m². Two coats at 14 m² a litre is 4.8 litres, so two 2.5 litre tins.
Why does a pattern repeat need more rolls?
Each strip has to start at the same point in the pattern, so it is rounded up to a whole number of repeats. The longer the repeat, the more is cut off and the fewer strips fit on a roll.