Wallpaper Calculator
Calculate how many wallpaper rolls you need for a room.
Wall area
45.00 m²
Rolls needed
10 rolls
Perimeter
18.00 m
How to use Wallpaper Calculator
Enter Room Height
Locate the 'Room Height' input field at the top left. Type your wall height in feet or meters (select your preferred unit from the dropdown). Standard ceiling heights are 8-10 feet.
Input Wall Width
Find the 'Wall Width' input field below height. Enter the total width of all walls you're wallpapering. Add all four walls together, or enter individual walls and click 'Add Wall' button.
Select Wallpaper Pattern Repeat
Choose your pattern repeat from the 'Pattern Repeat' dropdown (0 inches, 6 inches, 12 inches, or 18 inches). Larger repeats require more material. Check your wallpaper packaging for this specification.
Set Roll Coverage Size
Select your wallpaper roll size from the preset options: US Standard (56 sq ft), European (57 sq ft), or Asian (27-30 sq ft). Most US wallpaper is 27 inches wide × 27 feet long = 56 sq ft.
Account for Windows and Doors
Toggle 'Deduct Openings' switch ON. Enter the number of standard windows and doors to subtract their square footage from your total wall area. Each standard window/door ≈ 20 sq ft.
View Your Results
The 'Rolls Needed' result displays in the green results box on the right. The calculator adds 10% waste buffer automatically. Round up to the nearest whole roll and add 1 extra for mistakes.
Related Tools
Wallpaper calculator: how many rolls do you need?
Wallpaper calculator: how many rolls do you need?
Calculate exactly how many wallpaper rolls you need for any room at ToolHQ's wallpaper calculator, accounts for wall dimensions, doors, windows, and pattern repeat. Free, no account required.
Ordering too few rolls is a major problem because wallpaper from different dye lots can vary in color. Ordering too many wastes money. Getting the number right the first time requires accounting for room dimensions, wall openings, roll coverage, and, if your wallpaper has a pattern, the repeat distance that adds waste with every drop.
ToolHQ's wallpaper calculator handles all of this. Enter your room measurements, roll specifications, and pattern repeat, and you get the number of rolls to order, with a recommended buffer included.
Key Takeaways
- Calculate rolls needed from room dimensions and roll coverage
- Deduct doors and windows from total wall area
- Pattern repeat adds waste, the calculator accounts for it automatically
- Always order 10-15% extra to account for waste and matching
- No data is stored or transmitted, all calculations run locally in your browser
How the wallpaper calculation works
The basic formula is:
- Calculate total wall area: perimeter x wall height
- Subtract openings: deduct door and window areas
- Adjust for pattern repeat: each strip must start at the same point in the pattern
- Divide by roll coverage: how much area each roll covers
- Round up: always round up to the nearest whole roll
The critical detail, pattern repeat: If your wallpaper has no pattern (or a random match), each strip can start anywhere. If it has a pattern, each new strip must align with the previous one. A 64cm (25-inch) pattern repeat means you may waste up to 64cm from every strip to maintain alignment. The larger the repeat, the more waste per roll.
All calculations run locally in your browser, no data is stored or transmitted.
Standard wallpaper roll sizes
Roll coverage varies significantly between American and European rolls:
| Roll type | Width | Length | Coverage (approx.) |
|---|---|---|---|
| American double roll | 27 inches (68.5 cm) | 27 feet (8.2 m) | ~56 sq ft / 5.2 sq m |
| American single roll | 27 inches (68.5 cm) | 13.5 feet (4.1 m) | ~28 sq ft / 2.6 sq m |
| European standard roll | 53 cm (21 inches) | 10 m (33 feet) | ~5 sq m / 53 sq ft |
| Wide European roll | 70 cm (27.5 inches) | 10 m (33 feet) | ~7 sq m / 75 sq ft |
Important note: American wallpaper is often sold by the "single roll" but packaged and priced as "double rolls." Always check the actual roll dimensions on the label and enter them directly into the calculator rather than relying on the label's "roll count."
Pattern repeat types and waste
The type of pattern match determines how much extra material you need:
| Pattern type | Description | Typical waste |
|---|---|---|
| No match (plain, texture) | No pattern to align | Minimal (5%) |
| Straight match | Pattern repeats horizontally across each seam, all strips start at same position | Moderate (10-15%) |
| Half-drop match | Pattern drops by half the repeat height on alternate strips | Higher (15-20%) |
| Random match | Pattern positions intentionally varied (grasscloth, linen textures) | Minimal (5%) |
For patterned wallpaper: Increase your calculated rolls by one full roll for smaller rooms, or by 10-15% for larger rooms. This buffer accounts for trimming waste at the top and bottom of each strip.
Mini-story 1: Claire was redoing her dining room and found a wallpaper she loved with a 32cm half-drop pattern. She measured the room (4.2m x 3.8m, 2.5m ceiling height) and entered the values into ToolHQ's wallpaper calculator along with the roll dimensions (53cm wide, 10m long) and the pattern repeat. The calculator returned 9 rolls needed, with a recommended order of 10. She ordered 10. After hanging, she had just over half a roll left, giving her a spare for future repairs, exactly right.
Calculate wallpaper rolls free at ToolHQ
How to use the ToolHQ wallpaper calculator
- Measure your room. Measure the width of every wall you plan to wallpaper, and the ceiling height. For a full room, you need all four wall widths plus the height.
- Measure doors and windows. Record the height and width of each door and window that breaks up your walls.
- Check your roll specifications. Find the roll width and roll length on the product page or packaging. If you have a patterned wallpaper, find the pattern repeat distance.
- Enter the values. Go to ToolHQ's wallpaper calculator and enter room dimensions, openings, roll specs, and pattern repeat.
- Read and round up. The calculator returns the number of rolls needed. Always order the recommended quantity with the buffer, not the bare minimum.
Tip for rooms with alcoves or chimney breasts: Measure these separately and add their areas to your total. If an alcove has three small walls, measure each wall individually and add the areas together before entering the total wall width.
Step-by-step calculation example
Room: 4m x 3.5m, 2.4m ceiling height. Two doors (2m x 0.8m each). One window (1.2m x 1.0m). European roll: 53cm wide, 10m long. No pattern repeat.
- Wall perimeter: (4 + 3.5 + 4 + 3.5) = 15m
- Total wall area: 15m x 2.4m = 36 sq m
- Door area: 2 x (2m x 0.8m) = 3.2 sq m
- Window area: 1 x (1.2m x 1.0m) = 1.2 sq m
- Net wall area: 36 - 3.2 - 1.2 = 31.6 sq m
- Roll coverage: 0.53m x 10m = 5.3 sq m per roll
- Rolls needed: 31.6 / 5.3 = 5.96, round up to 6 rolls
- With 10% buffer: 6.6, round up to 7 rolls
Order 7 rolls.
For related home improvement calculations, ToolHQ's paint calculator estimates how many liters or gallons of paint you need for any room, and ToolHQ's flooring calculator calculates square footage for tiles, planks, or carpet with a waste factor.
Mini-story 2: James was helping his elderly neighbor wallpaper a bedroom. They bought what seemed like plenty, eight rolls of a highly patterned wallpaper with a 45cm repeat. Halfway through the room, they realized they were going to run short because neither of them had accounted for the pattern waste. They checked the remaining wall area against the remaining rolls and realized they needed two more. They returned to the store, but the new rolls were from a different dye lot with a slightly different base color. The finished room had a noticeable color shift on the final wall. The lesson: always use a calculator with pattern repeat before buying.
Frequently asked questions
Do I need to deduct every door and window?
Yes, but not obsessively. Deducting full door and window areas gives you a conservative estimate that still accounts for the offcuts around openings. The waste from cutting around openings roughly offsets the savings, so most professionals deduct the opening area but do not go further.
What happens if I buy wallpaper from two different lots?
Wallpaper from different production runs (dye lots) can vary slightly in color or pattern registration. Always buy all the rolls you need from the same lot. If you are unsure, order one extra roll, it is much cheaper than reordering from a new lot and having a color mismatch.
Can I wallpaper over existing wallpaper?
Technically yes, but it is generally not recommended. Old wallpaper can bubble, peel, or create an uneven surface under new paper. Remove existing wallpaper first for the best result.
How much extra should I order?
For plain or random-match wallpaper, 10% extra is sufficient. For straight-match patterns, 10-15% extra. For half-drop patterns or large repeats (over 50cm), budget 15-20% extra.
Is the wallpaper calculator free?
Yes. ToolHQ's wallpaper calculator is completely free, with no account, no sign-up, and no usage limits.
The short version
Wallpaper calculation is more than dividing room area by roll coverage. Pattern repeat adds waste to every strip, roll sizes vary between American and European standards, and doors and windows reduce the required area. ToolHQ's wallpaper calculator handles all three factors: room dimensions, opening deductions, and pattern repeat adjustment. Enter your measurements and roll specs, and it returns the number of rolls to order with a recommended buffer. The most important rule: always order from the same dye lot, and always order a little more than the minimum.
For related home improvement tools, ToolHQ's paint calculator estimates paint quantity by room area and coats, and ToolHQ's flooring calculator calculates material for any flooring type with a waste factor. Explore more calculator tools at ToolHQ.
Calculate wallpaper rolls free at ToolHQ