A Wallpaper Calculator helps you estimate the total wall area of a room, the number of wallpaper rolls required, and the expected wallpaper cost. Enter your room length, width, height, wallpaper roll coverage, and cost per roll to plan your decorating project more confidently.
This calculator is useful for bedrooms, living rooms, hallways, offices, and other spaces with four walls.
How to Use the Wallpaper Calculator
Step 1: Measure Your Room
Measure the length, width, and height of the room. Use the same unit for every measurement, such as feet or metres.
Step 2: Enter Wallpaper Roll Coverage
Enter the coverage area of one wallpaper roll. Check the product label for the exact usable coverage.
For example, a roll may cover 36 square feet.
Step 3: Enter the Cost Per Roll
Enter the price of one wallpaper roll. The calculator uses this value to estimate the wallpaper material cost.
Step 4: View Your Results
The calculator estimates:
- Total wall area
- Wallpaper rolls needed
- Total wallpaper cost
How to Calculate Total Wall Area
For a rectangular room with four walls, calculate the wall area by adding the area of each pair of opposite walls.
Total Wall Area=2×(Length×Height)+2×(Width×Height)
This formula assumes that all walls have the same height.
How to Calculate Wallpaper Rolls Needed
Divide the total wall area by the coverage provided by one wallpaper roll. Always round the answer up because wallpaper rolls are sold as whole rolls.
Rolls Needed=⌈Roll CoverageTotal Wall Area⌉
How to Calculate Wallpaper Cost
Multiply the total number of wallpaper rolls by the price of one roll.
Total Wallpaper Cost=Rolls Needed×Cost per Roll
Example Calculation
Suppose a room has the following measurements:
- Length: 15 feet
- Width: 10 feet
- Height: 8 feet
- Wallpaper roll coverage: 36 square feet
- Cost per roll: $20
Step 1: Calculate Total Wall Area
Total Wall Area=2×(15×8)+2×(10×8)
Total Wall Area=240+160=400 ft2
The total wall area is 400 square feet.
Step 2: Calculate Wallpaper Rolls Needed
Rolls Needed=⌈36 ft2400 ft2⌉
Rolls Needed=⌈11.11⌉=12 rolls
You need approximately 12 wallpaper rolls.
Step 3: Calculate Total Wallpaper Cost
Total Wallpaper Cost=12×20=240
The estimated wallpaper cost is $240.
Important Wallpaper Planning Tips
- Check the wallpaper label for the exact roll coverage.
- Add extra wallpaper for pattern matching, trimming, repairs, and installation waste.
- Measure walls carefully before ordering.
- Subtract large doors and windows only if they will not be wallpapered.
- Keep unopened extra rolls from the same batch for future repairs.
- Use matching roll numbers or batch numbers to maintain consistent colour and pattern.
Frequently Asked Questions
How do I measure a room for wallpaper?
Measure the length, width, and height of the room. The calculator uses these dimensions to estimate the total area of all four walls.
How many square feet does a wallpaper roll cover?
Coverage varies by manufacturer and wallpaper type. This calculator can use 36 square feet as an example, but always check the product label for the exact coverage.
Should I buy extra wallpaper for pattern matching?
Yes. Pattern matching can create waste because the design must align between strips. Buy extra rolls for wallpapers with large, repeating, or complex patterns.
Should I subtract doors and windows from the wall area?
You can subtract large doors and windows if they will not be wallpapered. However, keeping a small allowance is helpful for trimming, pattern matching, and repairs.
Why do I need to round up wallpaper rolls?
Wallpaper is sold in full rolls. Rounding up ensures you have enough material to cover the walls and handle normal cutting waste.
Does the wallpaper cost include paste and installation?
No. The calculator estimates wallpaper roll cost only. Add the cost of paste, primer, tools, preparation, delivery, and installation separately.
Can I use this calculator for one wall?
Yes. For a single feature wall, multiply that wall’s width by its height, then divide by the coverage area of one wallpaper roll.
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