Pattern repeat and half-drop match included
Wallpaper CalculatorHow Many Rolls of Wallpaper Do I Need?
Work out exactly how many wallpaper rolls to buy for a room or a feature wall. Enter your walls, choose a roll size and add the pattern repeat, and this wallpaper calculator counts the strips you need, how many fit in each roll and the total rolls, cost and waste. It even draws your walls strip by strip so you can see which roll each drop comes from.
- 5 roll sizes + custom
- Strip method accuracy
- Pattern repeat and match
- 3 tools in one
Doors, windows, trim and price
Doors are taken as 0.9 × 2.1 m and windows as 1.2 × 1.2 m. Only whole strips they save are removed, which keeps the estimate safe.
Your walls, strip by strip
Each colour is one roll. Dashed lines mark the corners between walls.
See how one roll is cut into strips for your wall height. Uses the roll size, pattern and trim from the first tab.
Cutting plan for one roll
Red dashed lines show the cuts. The hatched part is left over.
A fast estimate from wall area alone. It is less precise than the strip method because it cannot see pattern repeats or short strips.
How to calculate wallpaper rolls
Professional decorators count strips, also called drops, rather than dividing area by roll size. A roll only produces whole strips, and any piece shorter than the wall is usually wasted. Therefore, the strip method gives a far more reliable answer.
Strips needed
wall width ÷ roll width, rounded upStrip length
wall height + trim, rounded up to the repeatHalf-drop extra
add half a repeat to each stripStrips per roll
roll length ÷ strip length, rounded downRolls needed
strips ÷ strips per roll, rounded upRoom perimeter
2 × (length + width)Straight match
The pattern lines up horizontally across every strip at the same height. Each strip starts at the same point in the repeat, so waste depends only on how the repeat fits your wall height.
Half-drop match
Every second strip is shifted down by half a repeat, creating a diagonal pattern. You need roughly half a repeat extra per strip, so these papers use more rolls.
Wallpaper rolls needed by room size
Rolls of standard 53 cm × 10.05 m wallpaper for a room with 2.4 m walls, using the strip method with a 10 cm trim allowance and the perimeter treated as one continuous run. Doors, windows and spare rolls are not included.
| Room size | Perimeter | Strips | Free match | 53 cm repeat |
|---|---|---|---|---|
| 3 × 3 m | 12 m | 23 | 6 rolls | 8 rolls |
| 3 × 4 m | 14 m | 27 | 7 rolls | 9 rolls |
| 4 × 4 m | 16 m | 31 | 8 rolls | 11 rolls |
| 4 × 5 m | 18 m | 34 | 9 rolls | 12 rolls |
| 5 × 6 m | 22 m | 42 | 11 rolls | 14 rolls |
With free match, each roll gives 4 strips of 2.5 m. With a 53 cm straight repeat, each strip grows to 2.65 m, so only 3 fit in a roll.
A wallpaper estimator decorators would use
Many wallpaper calculators divide area by roll size and add a guess for waste. This one counts real strips, respects the pattern repeat and shows you exactly how the rolls will be used.
True strip method
Counts whole drops and packs them into rolls, the same way a professional plans the job.
Pattern aware
Free, straight and half-drop matches with any repeat length are handled correctly.
Walls of any height
Add each wall separately for feature walls, alcoves or rooms with different heights.
Visual strip map
See every strip on your walls, coloured by the roll it comes from.
Roll cutting plan
View exactly where to cut a roll and how much is left over for your wall height.
Metric and imperial
European, wide and US double rolls, or enter any custom roll size.
How to measure for wallpaper
Measure the walls
Measure each wall's width and the height from skirting to ceiling at its tallest point.
Check the label
Find the roll width, length and pattern repeat on the label or product page.
Enter the details
Choose whole room or individual walls, then add the roll size, match type and repeat.
Buy one batch
Buy all rolls with the same batch number, plus a spare for repairs and mistakes.
Painting the other walls? Work out how much you need with the paint calculator, and measure floor space with the square footage calculator.
Wallpapering tips that save money
Match batch numbers
Colours can vary slightly between print batches, so buy every roll from the same batch.
Keep a spare roll
A spare roll covers cutting mistakes and future repairs, and matching it later can be hard.
Use short offcuts
Leftover pieces are perfect above doors and below windows, which reduces waste.
Start at a focal point
Hang the first strip on the main wall so the pattern is centred where people look most.
Prepare the walls
Fill cracks, sand smooth and prime. Good preparation stops seams lifting later.
Check paste coverage
Paste coverage varies by brand and paper weight, so check the packet before you buy.
Wallpaper calculator FAQs
How many rolls of wallpaper do I need?
Divide the total wall width by the roll width to get the number of strips. Then find how many strips of your wall height fit in one roll. Divide the strips by strips per roll and round up. For example, a 4 × 3.5 m room with 2.6 m walls needs about 30 strips of standard 53 cm paper.
How much does one roll of wallpaper cover?
A standard 53 cm × 10.05 m roll has about 5.3 square meters of paper. After trimming and pattern matching, you will usually cover around 4.5 to 5 square meters.
What is a wallpaper pattern repeat?
The pattern repeat is the vertical distance before the design starts again. Larger repeats mean more paper is cut off to line up each strip, so you need more rolls.
What is the difference between straight and half-drop match?
In a straight match, the pattern lines up at the same height on every strip. In a half-drop, every second strip is moved down by half a repeat, so you need about half a repeat more paper per strip.
Should I subtract doors and windows?
Only partly. You still need short pieces above doors and around windows. This calculator removes only the whole strips that openings save, which avoids running short.
Why should I buy an extra roll?
An extra roll from the same batch covers cutting mistakes and future repairs. Rolls from a different batch may differ slightly in colour.
How many wallpaper rolls for a 12 × 12 ft room?
With 8 ft walls and US double rolls of 20.5 in × 33 ft, a free-match paper needs roughly 29 to 32 strips, three per roll, so about 10 to 11 double rolls before doors, windows and a spare.
Is the area method accurate for wallpaper?
The area method is a quick check, but it often underestimates because it cannot see leftover pieces or pattern repeats. Use the strip method for your final order.
Order the right number of rolls
Running short halfway through a room is frustrating, and over-buying wastes money. Use this wallpaper calculator to get an accurate roll count, see the cutting plan and start your project with confidence.