Free tool · No signup

Wallpaper calculator

Enter your wall size and your roll size to see how many rolls to buy. The calculator counts full strips, so it allows for the pattern repeat and trimming.

Updated October 2026

Your walls

What are you papering?

Whole roomOne wall

Length

Width

Wall height

Floor to ceiling openings to leave out

Optional. Add the width of patio doors or built-in wardrobes.

Your paper

Roll size

Roll width

Roll length

Pattern repeat

0 for a plain paper.

Wallpaper to buy

10 rolls

29 strips of 8 ft 4 in, 3 strips per roll. Buy one spare roll from the same batch.

Try a new look on your room first

3 designs free at signup. No card required.

Rolls for common room sizes

For US double rolls of 20.5 inches by 33 feet, a plain paper and no openings.

Room	8 ft walls	9 ft walls
10 x 10 ft	8 rolls	8 rolls
10 x 12 ft	9 rolls	9 rolls
12 x 12 ft	10 rolls	10 rolls
12 x 14 ft	11 rolls	11 rolls
14 x 16 ft	12 rolls	12 rolls

How the wallpaper calculator works

Wallpaper goes on in vertical strips, so the calculator counts strips, not square feet. First it finds how many strips fit across your walls: the width of the walls divided by the width of one roll, rounded up.

Then it finds how many full strips you can cut from one roll. Each strip is the wall height, plus 4 inches (10 cm) to trim at the top and bottom, plus one pattern repeat so the pattern lines up. The number of rolls is the strips you need divided by the strips per roll, rounded up.

This is the method paper hangers use. It is more reliable than dividing the wall area by the roll area, because the piece left at the end of each roll is often too short for a full strip.

Doors and windows

The calculator does not take away normal doors and windows. The pieces above a door and below a window still need paper, and the leftover end of each roll usually covers them. For a wide opening that goes from floor to ceiling, such as a patio door or a built-in wardrobe, enter its width in the field for openings to leave out.

Roll sizes

Roll sizes differ by country and brand, so check the label before you trust any result. Many wallpapers sold in the US come in double rolls of about 20.5 inches by 33 feet. The standard European roll is 0.53 meters by 10.05 meters. Murals and wide papers use other sizes. Pick the closest preset, then edit the width and length to match your paper.

Pattern repeat and match

The pattern repeat is the distance before the design starts again. It is printed on the label. A plain or random paper has no repeat, so enter 0.

A straight match lines up across every strip at the same height. A drop match lines up halfway down the next strip. Both waste paper at the top of each strip, and the calculator allows one full repeat per strip, which covers either kind.

Buy one extra roll

Rolls are printed in batches, and two batches of the same paper can differ a little in color. Buy every roll with the same batch number, and buy one more than you need. A spare roll covers a cutting mistake, and it lets you repair a damaged strip years later with an exact match.

Wallpaper calculator questions

How many rolls of wallpaper do I need for a 12x12 room?

About 10 US double rolls for 8 foot walls and a plain paper. That counts 29 strips at 3 strips per roll, with no doors or windows taken away. Add one spare roll from the same batch.

How do I calculate wallpaper rolls?

Divide the width of your walls by the roll width to get the number of strips. Divide the roll length by the wall height plus trim and pattern repeat to get strips per roll. Divide the first number by the second and round up.

Do I subtract doors and windows?

Not for normal doors and windows. The leftover end of each roll covers the short pieces above and below them. Leave out only wide openings that run from floor to ceiling.

What does pattern repeat mean?

It is the height of one copy of the design before it starts again. A larger repeat wastes more paper per strip, so it can add rolls to the total.

How big is a roll of wallpaper?

In the US, many papers come in double rolls of about 20.5 inches by 33 feet. The standard European roll is 0.53 by 10.05 meters. The label on your paper gives the exact size.

Can I see how my room looks before I buy wallpaper?

remyhomeai redesigns a photo of your room in 7 styles and 39 palettes, so you can test a new look before you commit. It does not apply a specific wallpaper pattern. You get 3 free designs at signup, with no card required.