It is a good idea to double check your numbers, since you’ll be basing your wallpaper amount off of them. If your room has baseboards, leave those out of your measurements unless you plan on wallpapering over them.
For example, if your wall is 5 feet (1. 5 m) x 7 feet (2. 1 m), multiply those numbers to get 35 square feet (3. 3 m2).
For example, if you have 3 walls in a room that are all 35 square feet (3. 3 m2), add 35 square feet (3. 3 m2) + 35 square feet (3. 3 m2) + 35 square feet (3. 3 m2) to get 105 square feet (9. 8 m2) for the whole room. Some websites have wallpaper calculators to help with these conversions, but they may be inaccurate, so make sure to always check your math.
These calculations do not have to be exact and can be done quickly since they are just to help you avoid over-ordering large amounts of wallpaper.
For example, if your room is 50 square feet (4. 6 m2), and your wallpaper roll has 25 square feet (2. 3 m2) of usable paper, you will need 3 rolls of wallpaper to cover your entire room and to have some extra left over.
For example, if your pattern repeat number is 18 inches (46 cm) (or 1. 5 feet (0. 46 m)), and your wallpaper roll contains 33 feet (10 m), multiply 1. 5 feet (0. 46 m) by 33 feet (10 m) to get 49. 5 square feet (4. 60 m2). This is how many square feet your wallpaper roll will cover. This type of patterned wallpaper creates the most waste, since you will have to cut a lot off while trying to line up your pattern. Often, these types of wallpapers are installed by professionals, but you can do them yourself with patience and planning.
