How many square feet does a roll of wallpaper cover?

A US single roll covers roughly 25 to 30 usable square feet and a double roll roughly 50 to 56. European rolls are often about 57 square feet. Always use the coverage printed on your label.

How much extra wallpaper should I buy for pattern repeat?

Plan on 10% for plain or small patterns and 15% to 20% for large repeats or drop matches. Buying all rolls from the same batch number also keeps the color consistent.

Should I subtract doors and windows?

Yes for normal openings, which is why the calculator removes 21 square feet per door and 15 per window. Some installers skip small windows to keep a safety margin.

How do I measure for wallpaper on a feature wall?

Measure the width and height of that single wall, multiply them and divide by roll coverage after adding waste. Most feature walls need between 3 and 6 rolls.

Wallpaper Calculator

Find out how many rolls of wallpaper you need for any room, with doors, windows and pattern waste taken out, plus an estimated total cost.

Room length

Room width

Wall height

Usable sq ft per roll

sq ft

Doors

Windows

Pattern waste

Price per roll

Each door subtracts 21 sq ft and each window 15 sq ft. Use 15% to 20% waste for large pattern repeats.

Rolls to buy

13 rolls

347.6 sq ft including waste

Breakdown

Wall perimeter: 44 ft
Gross wall area: 352 sq ft
Net wall area: 316 sq ft
Estimated cost: $520.00

How it works

Measure the length and width of the room along the floor and the height of the walls from the baseboard to the ceiling. The calculator adds the four walls together to get the perimeter, then multiplies by the height to find the gross wall area in square feet. If you only plan to cover one feature wall, enter that wall's width as the length and set the width to a very small number, or simply measure the wall area and work from there.

Next, enter how many doors and windows the room has. A standard interior door is about 3 by 7 feet, so each one removes 21 square feet. A typical window is about 3 by 5 feet, so each one removes 15 square feet. Large patio doors or bay windows should be counted as two openings to stay accurate.

Finally, check the label on your wallpaper for usable coverage per roll. In the United States a single roll usually covers about 25 to 30 square feet once trimming is accounted for, and a double roll covers about twice that. Add a waste percentage for matching the pattern: 10% for small or random patterns, 15% to 20% for large drop match repeats. The calculator divides the total by roll coverage and always rounds up to whole rolls.

Formula

perimeter = 2 × (length + width) gross area = perimeter × height net area = gross area − doors × 21 − windows × 15 rolls = ceil(net area × (1 + waste ÷ 100) ÷ coverage per roll)

Where:

21: = Square feet removed per standard door
15: = Square feet removed per standard window
waste: = Extra percentage for pattern matching and trimming

Worked example

A 12 by 10 foot bedroom with 8 foot walls has a perimeter of 44 feet and a gross wall area of 352 square feet. Taking away one door and one window leaves 316 square feet.

With 10% waste that becomes 347.6 square feet. Divided by 28 square feet per roll, that is 12.41, so you would buy 13 rolls. At $40 a roll the paper costs about $520.

Tips for hanging wallpaper with less waste

Start in the least visible corner of the room so the final seam, where the pattern rarely matches perfectly, ends up behind a door or in a corner. Use a level or laser line for the first strip, because every strip after it follows that first edge. Cut each drop a few inches longer than the wall height and trim the excess at the ceiling and baseboard with a sharp blade.

Check that every roll shares the same batch or lot number before opening any of them. Keep one spare roll for future repairs instead of returning it, since the same batch may not be available later. Smooth walls, a coat of primer and clean edges make the finished paper last for many years.

Frequently asked questions

Add up the width of every wall, multiply by the wall height, subtract doors and windows, add 10% to 20% for waste and divide by the usable square feet on one roll. Round up to the next whole roll.