Wallpaper Calculator – How Many Rolls Do I Need?
This wallpaper calculator shows how many rolls you need to cover your walls. Enter the width and height of each wall in feet, the roll width and length from the label, any pattern repeat and the doors and windows you will not cover. The tool counts the strips each wall needs, works out how many strips fit on one roll after matching the pattern, and adds a waste allowance. It also shows a simple area-based estimate to compare. US rolls are often 20.5 inches wide and 33 feet long as a double roll, but always check the label before you buy and buy all rolls from the same batch.
Wallpaper Calculator
Calculate how many wallpaper rolls you need from wall sizes, roll width and pattern repeat.
How to use the Wallpaper Calculator
- Enter the width and height of each wall in feet.
- Enter the roll width in inches and roll length in feet from the label.
- Add the pattern repeat in inches, or 0 for a plain wallpaper.
- Enter the area of doors and windows and the waste allowance.
- Read the number of rolls and strips, then round up when buying.
How it works
Strips per wall = wall width ÷ roll width, rounded up. Strip length = wall height + 4 inches for trimming, rounded up to a multiple of the pattern repeat. Strips per roll = roll length ÷ strip length, rounded down. Rolls = total strips with waste ÷ strips per roll, rounded up.
Features
- Multiple walls
- Strip method with pattern repeat
- Area method for comparison
- Doors and windows deduction
- Waste allowance
- Copy and print
Frequently asked questions
How do I calculate how many rolls of wallpaper I need?
Divide the total wall width by the roll width to get the strips, find how many strips fit on a roll from its length and your wall height, then divide and round up.
What is a pattern repeat?
The repeat is the vertical distance before the pattern starts again. Strips must be cut to a multiple of the repeat so the pattern lines up, which adds waste.
How much extra wallpaper should I buy?
Buy at least 10% extra for plain wallpaper and 15% or more for large patterns, so you have spare for mistakes and future repairs.
Should I subtract doors and windows?
Subtracting them only helps if the openings are large. This calculator uses the strip method, which does not shrink the count for small openings, and uses the opening area in the area-based estimate.
Why should I buy rolls from the same batch?
Color can vary slightly between print runs, and rolls from different batches may show a visible difference on the wall.