Standard rolls are 20.5 in (1.71 ft) or 27 in (2.25 ft)
Standard rolls are 33 ft (single) or 56 ft (double)
Rolls = ceil(((perimeter × height) - openings) × 1.1 / (rollWidth × rollLength))Total wall area is the room perimeter times the wall height. Each door takes about 21 ft² of wall, each window about 15 ft². Multiply the net wall area by 1.1 (10% waste for pattern matching and trimming), then divide by the area of one roll. Round up.
Enter room size, doors, windows, and roll dimensions. Get the number of rolls to buy with waste included.
Enter your room dimensions, the number of doors and windows, and your roll size. The calculator subtracts opening areas, adds 10% waste for trimming and pattern matching, then tells you how many rolls to buy. Works for standard US and European roll sizes.
Buying too little wallpaper means a second store trip, a possible dye-lot mismatch, and a stalled project. Buying too much wastes money. This calculator gives you the right number of rolls based on your room size, the openings in your walls, and the roll dimensions you have chosen.
You came here because
Common situations
- DIY home decoration: Estimate cost and material before starting a room.
- Property staging: Get accurate wallpaper material quotes for multiple rooms.
- Rental refresh: Plan a quick refresh using peel-and-stick rolls of known coverage.
- Accent walls: Calculate just one wall by entering its length as the full perimeter.
Under the hood
How the calculation works
- 1Measure your room length, width, and ceiling height.
- 2Count the doors and windows on the walls you are papering.
- 3Find the roll dimensions on the wallpaper packaging.
- 4Enter all values and read the rolls-needed number.
- 5Buy that exact number from the same batch to avoid color variation.
Show me
A real example
Example: 12 × 10 ft room with one door and two windows
- 1Perimeter = 2 × (12 + 10) = 44 ft
- 2Wall area = 44 × 8 = 352 ft²
- 3Openings = 1 × 21 + 2 × 15 = 51 ft²
- 4Net area = 352 - 51 = 301 ft²; with 10% waste = 331 ft²
- 5Roll area = 1.75 × 33 = 57.75 ft²; rolls = ceil(331 / 57.75) = 6 rolls
Watch out for
What can go wrong
- Forgetting the pattern repeat: A 24-inch pattern repeat wastes much more than a 6-inch repeat. For large patterns, add 15-20% waste instead of 10%.
- Mixing dye lots: Rolls from different batches can have slight color differences that show up under your finished wall. Always buy all rolls in one purchase from one lot.
- Ignoring ceiling height: A 9-foot ceiling needs 12.5% more material than an 8-foot ceiling for the same room footprint.
- Treating tall windows like normal windows: Large picture windows can be 30-40 ft². Measure each window if your room has unusual ones.
Glossary
Related concepts
| Term | Definition |
|---|---|
| Pattern repeat | The vertical distance after which the pattern repeats. A larger repeat means more waste matching the design across strips. |
| Single vs double roll | In the US a single roll is 33 ft; a double roll is 56 ft. Both are typically 20.5 in (1.71 ft) wide. |
| Dye lot | A batch number printed on each roll. Rolls from different lots may have slight color differences and should not be used in the same room. |
Make it better
Pro tips
- Buy one extra roll: A spare roll matches the dye lot and saves you if you damage a section or want to repaper years later. The cost of one extra roll is cheap insurance.
- Choose paste-the-wall for beginners: Paste-the-wall paper is more forgiving than paste-the-paper. The paper stays dry until applied, which means no soaking, no tearing.
- Match dye lots in writing: When buying online, message the seller and ask for confirmation that all rolls in your order ship from the same dye lot. Get it in writing.
- Order based on net area, not strips: Strip math (counting how many strips fit per roll) wastes the partial strips at the top and bottom. Area-based math captures real coverage.
Common questions
Frequently asked questions
Quick reference
Rolls Needed by Room Size
Standard 8 ft ceiling, 1 door, 2 windows, US roll (1.75 × 33 ft)
| Room size | Net area | Rolls needed |
|---|---|---|
| 8 × 10 ft | 237 ft² | 5 rolls |
| 10 × 12 fttypical | 301 ft² | 6 rolls |
| 12 × 14 ft | 365 ft² | 7 rolls |
| 14 × 16 ft | 429 ft² | 9 rolls |
| 16 × 20 ft | 525 ft² | 10 rolls |
For related calculations, try the Paint Calculator, Flooring Calculator, or Room Size Calculator. Browse all Calculator Online calculators for the full catalog.
Methodology
This calculator uses the standard wallpaper calculator formula. Results match those from established financial, scientific, and health references.
Reviewed by
Calculator Online Editorial Team. All formulas verified against authoritative sources before publication.
Last updated
2026-05-24