Use Bankrate’s wallpaper measurement calculator to determine how many rolls of wallpaper you'll need to complete your home improvement project. 

A standard roll of wallpaper gives you about 35 square feet, but waste and pattern matching usually take this down to about 27 usable square feet per roll. 

Knowing exactly how much wallpaper you will need will help you pinpoint the potential cost and organize your budget. This is especially useful if you need a home improvement loan to help cover costs.

How to measure for wallpaper

Similar to measuring for flooring, you will need to get an accurate area of each wall that you plan to add wallpaper to. This means measuring the height of the wall from floor to ceiling — including baseboards or crown molding — then measuring the length of each wall from corner to corner. Multiply each wall length together by the height of the room to get the area of each wall. Then divide that number by the size of the wallpaper roll to get the number of rolls you will need for your project.

Alternatively, you can add the lengths of the walls together to get the perimeter, then multiply this number by the wall height to get the room’s total area. Whichever route you take, you should be able to get an accurate measurement to determine how many rolls you will need.

How to calculate

To estimate the amount of wallpaper you room needs using the calculator, follow these steps.

1. Add up the lengths of all walls to get the distance around the room and enter this figure as the perimeter of the room. Round off to the nearest foot.
2. Enter the number of single doors (about 20 square feet), the number of double doors (about 40 square feet), small windows (10 square feet) and large windows (25 square feet).
3. Enter the square footage of any other openings or areas not to be wallpapered, such as a fireplace.
4. Enter the size of the roll of the paper you're using in square feet.
5. Click on "calculate." 
6. Allow for around 5% more material for waste. This is only an estimate.

Tips for buying wallpaper

When buying wallpaper, there are many things to consider. It is difficult to know exactly how a wallpapered room will look before installing it, but these steps can help:

• Always buy paper that carries the same lot, run or batch number. In addition to a pattern number, wallpaper usually is labeled with the lot, batch or run number, which indicates all the colors in that batch will be consistent. The same color in a different run or lot may be noticeably different. 
• Buy more than you need. When you install wallpaper, there is a margin of error. It is always better to have more than you need than less, especially if you have to make repairs down the line. 
• Consider patterns. If you are using patterned wallpaper, consider how that pattern will look in the space. Consider the scale of the pattern: larger patterns are best used in bedrooms or dining rooms — spaces where the pattern can be the focal point of the room. Also, consider how certain patterns affect how big a room feels. Horizontal patterns make a room look larger, while vertical patterns make the ceilings seem higher. 
• Order samples. It is important to test a wallpaper before buying enough to cover the space, especially if you are considering a bold pattern. Hang a sample of the wallpaper in the space before buying more to make sure you are happy with the color and pattern in person.

How to install wallpaper

Before you select a wallpaper, research materials. Most wallpapers in the U.S. are paper-backed vinyl, which is easier to install than other types of wallpaper. They also typically come pre-pasted, meaning you do not have to apply any adhesive.

Once you have chosen your wallpaper and are ready to apply it, follow these steps:  

1. Prep the walls. Remove plate covers and light fixtures. Fill holes with a nonshrinking joint compound and sand the walls to buff out imperfections. Cover the wall with primer. 
2. Roll on the paste. Use a paint roller to apply the paste to the wallpaper.
3. Book the paper before hanging. Fold the paper into thirds so that the paste can activate and the paper can soften.
4. Begin applying the paper. Start from an inside corner. Overlap the paper to ensure coverage. 
5. Gently smooth out the paper. Use a smoother to smooth down the paper once it is on the wall. Do this as you go. 
6. Wipe down the paper as you go. Use a sponge to clean off any paste residue. Squeeze the sponge while it is submerged in water to avoid creating suds on the paper.
7. Set paper edges with a roller. Make sure to roll over every seam as you go to avoid the paper curling. 

Required tools for installing wallpaper

If you plan on installing wallpaper yourself, this is what you will need:

• Chalk line
• Level
• Paint roller
• Straightedge
• Tape measure
• Taping knife
• Utility knife
• Scissors
• Sponge
• Wallpaper roll
• Wallpaper smoother
• “Wall size” primer/sizing product
• Wallpaper paste