Wallpaper Coverage Calculator
(How Many Rolls Do You Need?)
Enter your room's size, doors, windows and pattern type to find how many single or double rolls of wallpaper to buy, with a waste allowance built in.
Deducted as about 20 sq ft each
Deducted as about 15 sq ft each
Roll type
Pattern
Result
💡 Formula Guide
How to Work Out How Many Rolls of Wallpaper You Need
To find how many rolls of wallpaper you need, work out the net wall area, add a waste allowance for cutting and pattern matching, and divide by the usable coverage of one roll. Ordering too few rolls can be costly, because a later batch may not match, and ordering too many wastes money. This wallpaper calculator does the arithmetic and lets you choose the roll type and how much waste to allow for the pattern you have chosen.
Example. A 12 × 10 ft room with 8 ft walls has a perimeter of 44 ft and a wall area of 352 sq ft. One door (20 sq ft) and two windows (30 sq ft) reduce that to 302 sq ft. With 15% waste for plain paper, you need 347 sq ft, which is 12.4 single rolls at 28 sq ft or 6.2 double rolls. Buy 13 single rolls, or 7 double rolls. With a large pattern repeat and 35% waste the area rises to 408 sq ft, or 15 single rolls.
Roll Sizes and Waste Allowances
| Item | Figure used | Notes |
|---|---|---|
| US single roll | About 28 sq ft usable | Often sold as a double roll |
| US double roll | About 56 sq ft usable | Twice a single roll |
| Custom roll | You enter coverage | For other sizes, including European rolls |
| Plain or random pattern | 15% waste | Trimming and small errors |
| Small repeat | 25% waste | A middle value between plain and large-repeat paper |
| Large repeat or drop match | 35% waste | Matching wastes part of each strip |
Retailers publish their own coverage numbers because roll width, length and trim differ between brands, so use the label of the paper you plan to buy. When the roll's stated coverage is gross rather than usable, enter a lower figure in the custom box to reflect trimming.
Why Pattern Repeat Changes the Order
Plain and textured papers can be cut wherever needed, so waste is limited to trimming. A patterned paper has a repeat: the design has to line up from strip to strip, so each strip is cut from a specific point on the roll. With a large repeat, several inches or even a foot of each strip may be discarded to keep the pattern aligned. A drop match, where the pattern steps down between strips, wastes still more.
💡 Tip: if your design has a large repeat, check the retailer's calculator or ask them to confirm the rolls needed. They can count the strips per roll accurately, which is more precise than an area estimate.
Measuring and Ordering
- Measure each wall's height and width, or the room's perimeter, and use the tallest height for the calculation.
- Deduct openings sensibly. Standard doors and windows come off, but leave the calculation generous for irregular or sloping walls.
- Order all rolls together and check the batch numbers match, since colour varies between print runs.
- Keep a spare roll for repairs, particularly with expensive or discontinued designs.
The floor area helps too: the Room Area Calculator gives you dimensions to reuse. If you plan to paint the other walls, use the Paint Coverage Calculator, and for the floor try the Tile & Flooring Calculator. Treat any calculator as an estimate and confirm quantities with the retailer before ordering patterned paper.
Frequently Asked Questions About How Many Rolls to Buy
How many rolls of wallpaper do I need?
Find the net wall area, add a waste allowance and divide by the usable coverage of a roll. For a 12 × 10 ft room with 8 ft walls, one door and two windows, the net area is 302 sq ft. With 15% waste that is 347 sq ft, which needs 12.4 single rolls of about 28 sq ft, so buy 13 single rolls or 7 double rolls.
How much does one roll of wallpaper cover?
A US single roll gives roughly 28 usable square feet, and a double roll about twice that. Rolls are sold by the double roll in many stores, so check the label for the coverage of the roll you are buying. Rolls in other countries use different widths and lengths, so use the custom option for those.
How much extra wallpaper should I buy?
Around 15% extra is common for plain or random-match paper, and up to around 35% for patterned paper with a large repeat, since matching the pattern wastes part of each strip. The small-repeat option uses 25%, a middle value rather than a fixed standard. Ask the manufacturer for their guidance.
What is a pattern repeat?
It is the vertical distance before the design starts again. Wallpaper with a repeat has to be lined up from strip to strip, so each strip is cut longer and offcuts cannot always be reused. The larger the repeat, the more paper is wasted.
How do I subtract doors and windows?
A standard door is about 20 sq ft and a standard window about 15 sq ft, and the calculator deducts those from the total wall area. Many people deduct less for very small windows or not at all, to leave a margin for mistakes.
Do all the rolls need to be from the same batch?
Yes, buy all your rolls at once and check the batch or run numbers match. Colour and pattern can vary between print runs, and a mismatch is very visible on adjoining walls.
Can I use this for a single feature wall?
Yes. For one wall, multiply its width by its height, subtract any openings, add your waste allowance and divide by the coverage per roll. For example, a 10 ft wide by 8 ft high wall with no openings and 15% waste needs 80 × 1.15 = 92 sq ft, or 3.3 single rolls, so buy 4.
Is the result exact?
It is an estimate. The area method is quick and works well for plain paper, but a strip-by-strip count can differ for tall walls or large repeats. Ask the manufacturer or your retailer to confirm the number of rolls for a patterned design before you order.
Last Updated: September 2026 | Uses planning figures: about 28 usable sq ft per US single roll, 15% waste for plain and up to about 35% for patterned paper. Check your wallpaper's label for its actual coverage.