How do I calculate how much wallpaper I need?

Measure the total wall area by calculating the perimeter of the room (2 x length + 2 x width) and multiplying by the ceiling height. Subtract the area of doors (about 21 sq ft each) and windows (about 15 sq ft each). Then divide by the usable coverage per roll. Our calculator handles all of this automatically.

What is a standard wallpaper roll size?

In the US, a standard single roll is 20.5 inches wide by 33 feet long, covering approximately 56 sq ft. European rolls are typically 21 inches wide by 33 feet long. Double rolls (the most common retail size) are twice the length at 66 feet.

What is pattern repeat and how does it affect quantity?

Pattern repeat is the distance between where the pattern starts over on the wallpaper. A larger repeat means more waste per strip because you need to align the pattern between strips. A 12-inch repeat can add 10-15% more wallpaper needed. Zero repeat (solid or random patterns) produces the least waste.

How do I measure a room for wallpaper?

Measure each wall's width and add them together for the perimeter. Measure the ceiling height (most rooms are 8 feet). Count the number of standard doors and windows. You don't need to measure around outlets or light switches as the waste factor covers those small cutouts.

Should I order extra wallpaper rolls?

Yes, always order 1-2 extra rolls beyond what the calculator suggests. Wallpaper is printed in dye lots, and colors can vary slightly between batches. Having extra ensures you can make repairs or cover mistakes during installation.

Can I wallpaper over existing wallpaper?

It's generally not recommended. Old wallpaper can bubble, peel, or create an uneven surface. For the best results, remove old wallpaper, repair the wall surface, and apply a wallpaper primer before hanging new wallpaper.