UK decorating calculator
Wallpaper Calculator UK
Estimate wallpaper rolls, drops, pattern repeat, trimming allowance, spare rolls and optional cost with a UK-friendly strip method.
Last reviewed: 26 April 2026
Calculator inputs
Choose the wall type, enter your sizes, then check pattern and roll details before you calculate.
Result Card
Estimated wallpaper to buy
You should buy about 2 rolls. Try to buy all rolls from the same batch number.
Base rolls: 2
Based on a total wall width of 3.5 m and a roll width of 0.53 m.
10.05 m roll length / 2.5 m adjusted drop length
Base drop length: 2.5 m
8.4 m2 raw wall area with no deductions applied
Coverage uses full roll area, not just the usable drop area.
Leftover area is capped at zero and is only a guide.
Coverage deductions do not always reduce the number of drops you need
Doors and windows can reduce the area you cover, but you may still need full-height drops around openings. This estimate keeps strip count based on wall width for a safer buying guide.
How this estimate works
See the exact steps behind the estimate so the result stays easy to sense-check.
This calculator uses the wallpaper strip method. It estimates how many vertical drops are needed across the wall width, adjusts the drop length for trimming and pattern repeat, then works out how many drops can be cut from each roll. It rounds up to full rolls because wallpaper is sold by the roll.
- Build the wall list from your feature wall, room perimeter, or known total width.
- Calculate raw wall area and optional deductions for openings.
- Work out strips needed from total wall width and roll width.
- Adjust the drop length for trimming and optional pattern repeat.
- Divide the roll length by the adjusted drop length to get drops per roll.
- Round up to full rolls, then add any spare or safe-estimate extra rolls.
Wallpaper planning note: many UK wallpapers are sold in rolls around 0.53 m wide and 10.05 m long. Pattern repeat, trimming and batch numbers can affect how many rolls you should buy.
Example calculation
A worked example helps the user compare the result with a familiar everyday scenario.
A 3.5 m feature wall at 2.4 m high needs 7 full drops when the roll width is 0.53 m.
With a 10.05 m roll and 10 cm trimming allowance, each drop is about 2.5 m and one roll gives 4 drops.
That means the calculator recommends about 2 rolls before any optional spare rolls or cost estimate.
Simple wallpaper buying tips
A few simple checks can make a wallpaper order more accurate and easier to fit.
- Measure each wall separately.
- Check the wallpaper roll width and length.
- Check the pattern repeat on the label.
- Buy rolls from the same batch number.
- Add a spare roll for mistakes and future repairs.
- For large patterns or complex rooms, consider asking a decorator.
- Keep leftover wallpaper labelled for future repairs.
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Wallpaper calculator questions
Short answers to common wallpaper buying questions.
Why does this calculator use drops instead of only square metres?
Wallpaper is usually planned by vertical drops. Roll width, roll length, wall height, trimming and pattern repeat all affect how many full drops one roll can provide.
Should I subtract doors and windows?
You can, but openings do not always reduce the number of full-height drops you need. This calculator uses deductions mainly for the coverage summary and keeps strip count safer for fitting.
What is pattern repeat?
Pattern repeat is the vertical distance before the wallpaper pattern starts again. Straight and offset matches can increase the drop length and the number of rolls you should buy.
Should I buy a spare roll?
Often yes, especially for patterned wallpaper, future repairs or awkward fitting. A spare roll can also help you keep the same batch number.
Estimate notice
This is an estimate. Actual wallpaper needs can vary depending on pattern matching, trimming, fitting around openings, roll yield, product batch variation and how the paper is hung.