How Much Wallpaper Do I Need Calculator

How Much Wallpaper Do I Need Calculator

Height of Walls (ft):
Sum Total Length of Walls (ft):
Number of Doors:
Number of Windows:
Width of wallpaper roll:
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How Much Wallpaper Do I Need Formula:

Wall area, - 20 square feet per door, - 15 square feet per window, and all of this divided by the usable number of square feet per roll (average). For American rolls this is:
0"-6": 32 square feet
7"-12": 30 square feet
13"-18": 27 square feet
19"-23": 25 square feet

How Much Wallpaper Do I Need Definition

Taking wall measurements isn’t always enough to estimate how much wallpaper you need. In addition to the square footage of where the wallpaper is, you have to calculate where it isn’t, how large the wallpaper roll is and how many mistakes you might make. Lucky for you, it’s easy to get more precise estimations with a wallpaper calculator.

Looking for a paint calculator? Check this one out after you calculate your wallpaper needs!

Measure the Height of the Walls

For the wallpaper calculator, you’ll need the height of the walls in feet. The trouble is that most measuring tapes measure in feet and inches. To accommodate those inches in the wallpaper calculator, you’ll have to turn them into decimals by dividing them by 12. For example, if your walls are 7 feet 9 inches tall, then you’ll enter 9.75 into the calculator because 9 divided by 12 is .75. Or check out our Inches to Feet calculator!

Slanted Ceilings: If your ceilings are slanted, then you’ll have to measure the average height of the walls. Start by taking the floor-to-ceiling measurement at the lowest point of the wall. To make sure that your measurements are accurate, always take each measurement at least twice before recording the number.

Next take the floor-to-ceiling measurements in the middle of the wall followed by the highest end. Divide the inches so that they’re all decimals. Finally average the measurements together. For example, if the measurements are 6.8, 7.2 and 7.8, add them together then divide by 3 to get 7.26 rounded up to 7.3.

Measure the Width of the Walls

For the second section, you’ll need to know the sum total width of the walls. That means the measurement of all of the walls added together. Start with the wall immediately to your left. Take a measurement — measure again to check your results — and write it down. Continue in a clockwise fashion until you have measured all of the walls. Next, divide the inches to make decimals. Finally, add all of the measurements together and enter that number into the “width” section in the calculator.

Doors and Windows

When buying wallpaper, you have to take into account the fact that the doors and windows don’t need covering. The wallpaper calculator takes the average width of windows and doors and subtracts them from the total amount of wallpaper that you need. That’s roughly 20 square feet per door and 15 square feet per window.

If your room contains large bay windows or double doors, you want to adjust your measurements accordingly. Just enter 1 for every average sized door and window but allow oversized apertures to count twice. For example, if I have one window and one set of double doors, then I would put “1” in the window box but “2” in the doors box.

The Width of the Roll

The width of the wallpaper roll is measured from one end of the tube in inches. These measurements you’ll need to take while at the wallpaper store or while shopping online. In most cases you won’t have to take your measuring tape out. The width of most wallpaper tubes is printed somewhere on the packaging. In rare cases, like when dealing with antique wallpaper, you may have to take out the measuring tape and measure by hand just to be sure.

Once you have the measurement on hand, click the pull down wallpaper length window. The wallpaper lengths are listed in ranges of 5 inches. Choose the range that your wallpaper’s width fits into.

After you enter all of the measurements, the calculator will estimate how much wallpaper you need to complete your job. This is a rough but useful measurement. However, if you’re an amateur wallpaper layer, consider adding 15% to the calculation to allow for any mistakes that you make. Also, if the wallpaper is antique or otherwise hard to find, consider buying an extra roll or two for mistakes or touch-ups several years down the line when the wallpaper may no longer be available.

How to Calculate How Much Wallpaper Do I Need

Let's be honest - sometimes the best how much wallpaper do i need calculator is the one that is easy to use and doesn't require us to even know what the how much wallpaper do i need formula is in the first place! But if you want to know the exact formula for calculating how much wallpaper do i need then please check out the "Formula" box above.

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