Quick Answer
To calculate how many rolls of wallpaper you need, you’ll need to measure the room and determine a few key details. Here is a quick rundown of what to do:
- Measure the length and height of each wall you want to cover.
- Calculate the total wall surface area by adding up the area of each wall (length x height for each wall)
- Determine how many square feet each roll covers (this info is on the wallpaper packaging)
- Divide the total wall surface area by the square footage each roll covers
- Round up to the nearest whole number – this is how many rolls you need
Knowing the dimensions of your walls, how much wallpaper is on each roll, and doing some simple math will give you an accurate number of rolls needed. Read on for more details and examples!
Measuring and Calculating Total Wall Surface Area
The starting point for figuring out how much wallpaper you need is to measure each wall you want to cover. This will allow you to calculate the total surface area of the walls.
Here are the steps:
- Use a tape measure to measure the length and height of each wall. Record these measurements.
- To get the surface area of each wall, multiply the length by the height. So if a wall is 10 feet long and 8 feet high, its area would be 10 x 8 = 80 square feet.
- Calculate the area for each wall and write it down.
- Add up the individual wall surface areas to get your total wall surface area.
So for example, if you measured:
- Wall 1: 10 ft long x 8 ft high = 80 sq ft
- Wall 2: 8 ft long x 8 ft high = 64 sq ft
- Wall 3: 6 ft long x 8 ft high = 48 sq ft
Your total wall surface area would be 80 + 64 + 48 = 192 square feet
This total square footage is what you’ll use to determine how many rolls you need.
Determining Square Footage per Roll
Now that you know your total wall surface area, you need to know how much wallpaper is on each roll. This info should be clearly stated on the wallpaper packaging or description.
Standard roll sizes include:
- 56 square feet
- 64 square feet
- 100 square feet
- 150 square feet
Let’s say the rolls you purchased are 64 square feet each. Write down the square footage per roll – you’ll need it for the next step.
Calculating Number of Rolls
Here comes the math! You’ll divide your total wall surface area by the square footage per roll to get the estimated number of rolls needed.
Continuing our example:
- Total wall surface area = 192 square feet
- Wallpaper rolls are 64 square feet each
192 square feet (total area) / 64 square feet (per roll) = 3 rolls
Three 64-square foot rolls will cover the 192 square feet of total wall space.
To make sure you purchase enough, always round up to the next full roll when your math gives you a partial roll.
What If You Have Doors or Windows?
When calculating how much wallpaper you need, don’t forget to account for doors and windows!
For each door or window, you’ll need to deduct its dimensions from the wall measurements before you calculate the area.
For example:
- Wall 1 is 10 ft long x 8 ft high = 80 sq ft
- Wall 1 has a 3 ft wide x 7 ft high window
To adjust for the window, deduct its area from the wall:
- Wall 1: 10 x 8 = 80 sq ft
- Window: 3 x 7 = 21 sq ft
- Wall 1 adjusted area = 80 – 21 = 59 sq ft
Do the same for any doors or other openings before adding up the total wall surface area. This will give you an accurate number to work with.
Ordering Extra Rolls
It’s always smart to order a few extra rolls over what your measurements indicate. Having 5-10% extra allows for errors, pattern matching, and waste.
Wallpaper can tear or become damaged during installation. Extra rolls ensure you always have enough to finish the job.
You may also be able to return unused rolls, but check the retailer’s return policy first. However, having too much is better than not having enough!
Tips for Accurate Measurements
Getting precise measurements is crucial for determining how much wallpaper to buy. Here are some tips:
- Use a steel tape measure and carefully measure to the nearest 1/8 inch.
- Always measure and calculate the surface area of each wall separately.
- Look for any uneven spots, indentations, or damaged areas on walls that may require more wallpaper.
- Measure the length and width of any windows, doors, outlets or switches and deduct them from the wall surface area.
- Consider skylights, ceilings, and any other architectural features or obstructions.
- For heights, measure from the floor to the ceiling – don’t eyeball it.
Taking careful measurements of each wall and feature will pay off with the correct amount of wallpaper.
Consider Repeat Patterns
For patterned wallpaper, you also need to account for the pattern repeat when calculating how many rolls you need.
The repeat is the length between identical parts of the pattern horizontally and vertically. This info should be provided on the label or in the description.
Add at least 2-3 inches for each repeat to the height measurement of each wall when figuring the area. This provides enough paper to match the pattern properly.
If the vertical repeat is 24 inches, measure from floor to ceiling then add 48-72 inches to allow for matching the repeat.
Doing this simple step prevents coming up short on paper when decorating with patterned wallpaper.
Use a Wallpaper Calculator
If all the measuring and math sounds daunting, you can always use a wallpaper calculator tool.
These handy calculators allow you to plug in the dimensions of each wall, then input the square footage per roll.
It does the calculations instantly and tells you exactly how many rolls are needed. Most also account for doors, windows and pattern repeats.
Wallpaper calculator tools are easy to find online and take the guesswork out of purchasing the right amount. Just be sure to take detailed measurements for best results.
Summary of Calculating Wallpaper Rolls Needed
To summarize, here are the key steps:
- Carefully measure the length and height of each wall.
- Deduct the area of any doors, windows or openings.
- Calculate the total wall surface area: length x height of each wall added together.
- Check the wallpaper packaging for the square feet per roll.
- Divide total wall area by square feet per roll.
- Round up to the next full number for the total rolls needed.
- Add a couple extra rolls for errors and waste.
Follow these steps, use a calculator, and order 5-10% extra for the best results. With some simple math and accurate measurements, you’ll end up with just the right amount of wallpaper.
Frequently Asked Questions
How do I calculate linear feet for a room?
To calculate linear feet, simply add together the length of each wall in the room. For example, if you have:
- Wall 1: 10 ft long
- Wall 2: 12 ft long
- Wall 3: 15 ft long
Your linear feet would be 10 + 12 + 15 = 37 linear feet.
This number can be useful for estimating rolls needed, but your most accurate determination will come from calculating total wall surface area in square feet.
What tools do I need to measure rooms?
The only tool you really need for measuring rooms is an accurate tape measure. A 25-foot steel retractable tape measure works best.
You may also want a measuring wheel for larger, open wall spaces. A laser distance measurer can also help if high ceilings make it hard to reach for measurements.
Have a pad and pencil on hand to record the length and height figures for each of your room’s walls.
Should I deduct electrical outlets and switches?
How do I calculate wallpaper for a stairwell?Measuring for wallpaper on a stairwell can be tricky. Here are some tips:
- Measure the height from floor to ceiling, and width from one wall edge to the other.
- For the length, measure each stair tread and riser separately.
- Add up the total length of all treads and risers together.
- Use the height, width and total stair length to calculate the total area.
- Have extra paper to accommodate angle changes,Matching patterns will also take more paper.
Take your time measuring to get the most accurate area calculation possible.
Conclusion
Figuring out how many rolls of wallpaper to buy for your project doesn’t have to be hard. Just carefully measure each wall surface area, account for doors, windows and repeat patterns.
Know how much wallpaper is on each roll then divide and round up to get the roll count. Order 5-10% extra for safety too.
Following the steps in this article will help you determine the exact number of rolls needed. Then you can decorate your hearts content with just the right amount of stylish, new wallpaper.
