Wallpaper Calculator
Last updated: June 2026
Formula
Wall area = 2 x (length + width) x height. Net area subtracts doors and windows. Rolls = ceiling(net area / 5m²), plus waste for pattern repeat.
| Room size | Height | Typical rolls |
|---|---|---|
| Small | 2.4m | 8-10 |
| Medium | 2.4m | 12-14 |
| Large | 2.4m | 16-18 |
About this calculator
Estimate how many wallpaper rolls to buy for a UK room using room dimensions, doors, windows, wall count, and pattern repeat. It helps you avoid under-ordering, especially when matching patterns or papering only selected walls.
Wallpaper roll method
The calculator uses metric dimensions and practical UK planning assumptions. Results are estimates, so check product labels, site conditions, and supplier guidance before ordering materials.
- perimeter = 2 x (room length + room width)
- net wall area = perimeter x height - door/window deductions
- rolls = ceiling(net wall area / 5m²), plus pattern waste and one spare roll
How to use the wallpaper calculator
- Choose the project type or measurement mode where the calculator offers one.
- Enter all dimensions in metric units.
- Add allowances such as coats, waste, pattern repeat, roll width, or bag size where relevant.
- Review the main highlighted result first.
- Check secondary results such as packs, bags, rolls, posts, or tin combinations.
- Round up to supplier pack sizes and confirm the label coverage before buying.
Worked examples
All walls in a medium room
Input: 4m x 3m room, 2.4m high, 1 door, 1 window
Calculation: Perimeter 14m x 2.4m = 33.6m². Less 3.3m² = 30.3m². 30.3 / 5 = 6.06.
Result: Round to 7 rolls, then consider 8 rolls including one spare.
Pattern repeat allowance
Input: 7 base rolls with a pattern repeat
Calculation: 7 x 1.15 = 8.05.
Result: Round to 9 rolls, then consider a spare if the batch must match.
How to measure for wallpaper
Measure the room length, width, and height in metres. For all walls, the calculator uses the room perimeter. For selected walls, it scales the wall area by the number of walls entered.
Doors and windows are deducted using practical average sizes, but complicated alcoves, chimney breasts, bay windows, and sloped ceilings need manual checking.
Pattern repeat explained
A pattern repeat means each drop has to line up with the previous drop. This creates offcuts, so patterned wallpaper usually needs more rolls than plain wallpaper.
UK vs European roll sizes
A common UK wallpaper roll is about 52cm wide and 10m long. Some designer or European papers use different widths and lengths, so adjust your estimate if the roll label is different.
Common mistakes
- Mixing centimetres, millimetres, and metres without converting first.
- Ordering exact quantities with no allowance for cuts, waste, damage, or uneven surfaces.
- Forgetting that products are sold in tins, packs, bags, rolls, or boards rather than exact calculated quantities.
- Using average deductions or coverage rates when the project has unusual shapes, textures, slopes, or access limits.
- Not checking manufacturer instructions before final ordering.
Home improvement estimate disclaimer
This calculator is for general DIY planning only. It is not a substitute for a professional survey, structural design, building control advice, manufacturer instructions, or installer measurement.
- Actual product coverage and pack sizes vary by supplier.
- Site conditions can change material quantities.
- Structural, roofing, electrical, gas, and regulated building work may need qualified advice.
Frequently asked questions
Why add one spare roll?
A spare roll helps with mistakes, trimming, pattern matching, repairs, and batch matching. Buying later may mean a different batch shade.
Does one roll really cover 5m²?
A standard 0.52m x 10m roll has about 5.2m² before trimming, so 5m² is a practical planning allowance.
Should I deduct windows?
Yes for a broad estimate, but do not over-deduct if paper is needed around reveals, recesses, or awkward cuts.
What if I only wallpaper one wall?
Select No for all walls and enter the number of walls. For a feature wall, manually check the actual wall width if it differs from the room average.
Can I mix rolls from different batches?
It is best to avoid mixing batches because shade can vary slightly between production runs.
Related calculators
- Paint Calculator
- Flooring Calculator
- Area Calculator
- Metres to Feet Converter
What does this mean?
This calculator is designed to help you understand the likely number before you make a decision or start an application.
Your result should be checked against official UK guidance, especially if your circumstances include dependants, exemptions, prior leave, or a complex immigration history.
Treat the figure as a planning tool rather than legal advice. Where the answer affects an application deadline or major payment, speak to an authorised adviser.
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