How do I use the Wallpaper Calculator?

Pick your unit (metres or feet) and enter the room length, width, and ceiling height. Enter how many doors and windows the room has - their area is subtracted from the total. Enter the roll width and length from your wallpaper packaging. Set a wastage percentage (10% for plain wallpaper, 15-20% for patterned) and click Calculate.

Is the Wallpaper Calculator free?

Yes, the Wallpaper Calculator on ToolHaven is completely free to use. No signup or registration is required.

Wallpaper Calculator

Calculate how many rolls of wallpaper you need for a room. Enter the room dimensions, number of doors and windows (they get subtracted), roll size, and wastage percentage.

Room Length (m)

Room Width (m)

Ceiling Height (m)

Number of Doors

Number of Windows

Wastage %

Roll Width (m)

Standard UK roll: 0.53m

Roll Length (m)

Standard UK roll: 10m

How to use

Pick your unit (metres or feet) and enter the room length, width, and ceiling height.
Enter how many doors and windows the room has - their area is subtracted from the total.
Enter the roll width and length from your wallpaper packaging.
Set a wastage percentage (10% for plain wallpaper, 15-20% for patterned) and click Calculate.

Related tools:

Calculating wallpaper rolls is one of the most common home improvement miscalculations. Most standard rolls are 52cm wide x 10m long, covering about 5 square metres. But pattern repeat - the length you waste aligning the pattern at each seam - can significantly increase consumption. A large pattern repeat (60+ cm) can waste an entire strip per drop in a large room.

The calculator takes room perimeter, wall height, doors and windows (areas not wallpapered), and roll dimensions. It adds a waste allowance and rounds up to whole rolls. Always buy one or two extra rolls from the same batch code - dye lots vary between production runs, and mismatched rolls on the same wall will show.

Frequently Asked Questions

What is a pattern repeat and how does it affect how many rolls I need?

Pattern repeat is the vertical distance after which the wallpaper pattern repeats. To align the pattern across seams, you often waste a portion of each strip. A 64cm pattern repeat on a 2.4m ceiling height wall means each drop requires 3.2m (2.4 + 0.8 for waste), not 2.4m. This increases roll count by 25-35% versus a plain wallpaper.

Should I subtract windows and doors from the calculation?

Yes, if they are large. A standard door opening (2m x 0.9m = 1.8 sqm) represents a meaningful saving. Small windows are often not worth subtracting since the strips still need to run top-to-bottom around them. The calculator lets you input door and window counts with standard dimensions.

How many rolls does a typical bedroom need?

A 4m x 4m bedroom with 2.4m ceilings and one door, using standard 52cm x 10m rolls, needs approximately 8-10 rolls for a plain pattern. A large repeating pattern could push this to 12-14 rolls. Measure carefully and add 10% waste regardless.