When installing wallpapers at home, you should have an idea of how much square footage you need. Using this wallpaper calculator helps you avoid situations where you might buy less and this could send you back to the home depot or buying too much which might strain your finances.

## How to use the wallpaper calculator?

This wallpaper calculator may look intimidating but it’s really easy to use. This online tool is also known as a wallpaper estimator and you can use it to help you determine how much wallpaper you need for your project. For wallpaper with a repeating pattern, you can use a wallpaper calculator with repeat. **But for this one, here are the steps:**

- First, choose the Project Type from the drop-down menu.
- Enter the values of the Room Length, Room Width, and Room Height then choose the unit of measurement from the drop-down menu.
- You can also enter the Room Area and choose the unit of measurement from the drop-down menu.
- For the Doors, enter the values of the Door Height, Door Width, and Number of Doors or simply the Door Area and choose the unit of measurement from the drop-down menu.
- For the Windows, enter the values of the Window Height, Window Width, and Number of Windows or simply the Window Area and choose the unit of measurement from the drop-down menu.
- For the Wallpaper itself, enter the value of the Cost per Roll, Roll Length, Roll Width, and a value for Pattern Repeat if applicable.
- After entering all these values, the wallpaper estimator gives you the values for the Number of Wallpaper Rolls, the Adjusted Room Height, the Adjusted Room Area, the Number of Rolls, and the Total Cost.

## How do I calculate how much wallpaper I need?

**All you need for your wallpaper calculator are basic data including:**

**Room Dimensions**

You need the usual width, length, and height of the room. If you have a room with a different shape other than the rectangular cuboid, you can solve the area of the shape and input this directly into the calculator.**Doors and windows**

You can either leave the default dimensions of doors and windows or customize them. Once you enter the dimensions into the wallpaper estimator, their areas are automatically calculated.

**Once you have gathered and typed in all these values, the wallpaper calculator with repeat solves the following for you:**

- Adjusted Height
- Adjusted Room Area
- Number of Rolls
- Total Cost

## How do you calculate wallpaper needed for a pattern repeat?

Wallpapers without patterns are easy to install and calculate. Unfortunately, most of the available wallpapers have a pattern or design and they require more materials than their solid counterpart. This is because you need to consider the pattern repeat.

Manufacturers indicate this on the label of the wallpaper or under its specifications you plan to purchase your wallpaper online. Let’s assume you want to install wallpaper with an 18-inch repeat pattern with 61-square-feet for each double roll which you plan to install on four walls. **Here are the steps:**

- Measure the height of your wall and convert it into inches.
- Divide the height by your wallpaper’s pattern repeat in inches.
- Multiply the value you get by the value of the pattern repeat. The resulting product will be the adjusted ceiling height which accommodates the pattern of your wallpaper. You use this value for calculating the wall covering quantity rather than the actual ceiling height.
- Convert the adjusted ceiling height into feet by dividing the value by 12.
- Measure the total width of the walls.
- Multiply the ceiling height with its width to get the room’s total area.
- To this area, add another 20% for waste allowance. The adjusted total area will then be 1.20 x actual area.
- Calculate the areas of windows or doors and subtract this from the square footage value you acquired. The result will be the square footage that you need.
- Round the result to the next whole number to find the rolls that you need to order for the job.

## How many drops do you get out of a roll of wallpaper?

There are usually three drops in a roll of wallpaper. It’s recommended to use any leftovers for the space above doors or above and under windows. It’s a common practice among good retailers to take back extra unopened rolls. But it’s also a good practice to retain some wallpaper in case some pieces get marked or damaged.

## How much does a roll of wallpaper cost?

For sure, wallpapers enhance the decor of a room with their colors, patterns, and textures that would be impossible to manually create. The images of wallpapers can vary from simple repeated patterns to complex murals or even a combination of borders and patterns. On average, wallpaper installations can last between 15 – 25 years, or even more.

**Typical costs of wallpaper rolls**

- High-quality, basic wallpapers sell between $25 – $50 for one roll depending on the style and material. A typical room measuring 16′ x 20′ may require 16 – 20 rolls. The cost, therefore, can range between $400 – $1,000.
- Designer wallpapers are more expensive and can sell between $60 – $250 or even more for each roll. Using the same room dimensions, the cost for this will be between $960 – $5,000.
- Professional paperhangers may charge fees between $30 – $60 to install one roll for $480 – $1,000 just for the labor for a room with the same size. This brings the total cost, including the wallpaper to about $880 – $2,200 if you hire the services of professionals.

It becomes more expensive with designer wallpapers because mistakes here could be very costly. Professionals charge about 75% or more when installing designer wallpapers. This is about $1,000 – $8,800 or more for a room of the same size, depending on the wallpaper they use. - Large wallpaper murals cost between $200 – $800 but may cost as much as $1,000 – $2,000 and above depending on the design, subject matter, and size of the mural. Professional installations for an 8-panel mural can cost between $200 – $300 and these prices go higher depending upon the complexity.