How Much Wallpaper Do I Need? Measuring and Calculating Rolls
How to measure your walls, allow for the pattern repeat and work out your number of rolls, with worked examples for a feature wall, a whole room, a chimney breast and a stairwell
To work out how much wallpaper you need, measure the width of each wall and divide it by 0.48m to get the number of drops. Then work out how many drops you can cut from a 10.05m roll, once you have allowed for the pattern repeat and the 3cm of trimming margin at each end of every length. Divide one by the other, round up, and add a spare roll.
That is the whole method. Below it is set out step by step, with worked examples and the three places where people usually go wrong.
The numbers you're working with
- Roll width: 48cm (0.48m)
- Roll length: 10.05m
- Area per roll: 4.82m² on paper, and in practice closer to 3.5m² once a standard wall has been trimmed and pattern-matched
- Trimming margin: 3cm at each end of every length, cut off once the paper is on the wall
- Pattern match: straight match, so the design lines up at the same height across every length
- Pattern repeat: varies by design, and it is listed in the specification on every product page
In imperial measurements that roll is 19in × 33ft, which is the equivalent of an American double roll. It is the same roll either way, and only the units on the page change.
There is a roll estimator on every product page, and it is the quickest way to get a figure. Treat it as a guide rather than an order. It cannot see your ceiling height varying across a wall, a chimney breast, a stairwell drop or a bay, so measure up yourself before you commit to a quantity.
One thing worth understanding before you measure: the pattern repeat, not the wall, is what decides how much paper you waste. A design with a 24cm repeat gets more drops out of a roll than one with a 64cm repeat, because every length has to start at the same point in the pattern.
Step 1: Measure your walls
- Measure the height from ceiling to the top of the skirting board. Do it in two or three places along the wall and use the largest figure, because very few ceilings are level.
- Measure the width of each wall you intend to paper. If you are papering a whole room, measure each wall separately rather than pacing out the perimeter.
- Ignore doors and ordinary windows. Count the full width of the wall as if they were not there. The offcuts from above and below an opening are what you use to fill in around it, and deducting them is the most common way people end up a roll short.
- Deduct only very large openings, such as patio doors, a wide opening between two rooms, or a full wall of glazing.
Write the figures down wall by wall. If the heights differ, as in a stairwell or a room with a sloping ceiling, treat each wall as its own calculation.
Step 2: Work out your number of drops
A drop is one length of paper, floor to ceiling. Divide the width of the wall by 0.48 and round up to the next whole number.
A wall 3.6m wide: 3.6 ÷ 0.48 = 7.5, so you need 8 drops.
Always round up. Half a drop still needs a whole width of paper cut to make it.
Step 3: Work out your cut length
This is the step most calculators skip, and it is where the pattern repeat comes in.
- Take the wall height and add 3cm at the ceiling and 3cm at the skirting. That margin is there to be trimmed off once the length is on the wall, and it is what lets you cut a clean line against an uneven ceiling and skirting.
- Round that figure up to the next whole multiple of the pattern repeat. Because the design is a straight match, every length has to begin at the same point in the pattern, so anything left over is waste.
A 2.4m wall with a 48cm repeat: 2.4 + 0.06 = 2.46m. The next whole multiple of 0.48 is 2.88m (0.48 × 6). Your cut length is 2.88m.
The same wall with a 24cm repeat: the next whole multiple of 0.24 above 2.46m is 2.64m (0.24 × 11). Your cut length is 2.64m, and you have wasted 24cm less per drop.
Step 4: Work out drops per roll
Divide the roll length by your cut length, and this time round down. You cannot use most of a drop.
10.05 ÷ 2.88 = 3.49, so 3 drops per roll.
Step 5: Work out your rolls
Divide your total drops by your drops per roll, and round up.
8 drops ÷ 3 drops per roll = 2.67, so 3 rolls.
Then add one spare roll. Not because the maths is unreliable, but because an offcut is what repairs a scuff or a tear in three years' time, and because a wall almost always has one awkward corner nobody measured.
Worked example: a feature wall
A wall 3.6m wide and 2.4m high, in a design with a 48cm repeat.
- Drops: 3.6 ÷ 0.48 = 7.5, so 8 drops
- Cut length: 2.4 + 0.06 = 2.46, rounded up to 2.88m
- Drops per roll: 10.05 ÷ 2.88 = 3.49, so 3 drops
- Rolls: 8 ÷ 3 = 2.67, so 3 rolls, plus a spare
Worked example: a whole room
A room 4.2m × 3.6m with a 2.4m ceiling, in a design with a 24cm repeat. One door, one window, both ignored.
- Total wall width: (4.2 + 3.6) × 2 = 15.6m
- Drops: 15.6 ÷ 0.48 = 32.5, so 33 drops
- Cut length: 2.46, rounded up to 2.64m
- Drops per roll: 10.05 ÷ 2.64 = 3.81, so 3 drops
- Rolls: 33 ÷ 3 = 11 rolls, plus a spare
Worked example: a chimney breast
A breast 1.4m across the front with two 0.4m returns, 2.4m high, 48cm repeat. Measure the three faces separately.
- Front: 1.4 ÷ 0.48 = 2.92, so 3 drops
- Each return: 0.4 ÷ 0.48 = 0.83, so 1 drop each, making 2 drops
- Total: 5 drops. At 3 drops per roll, that is 2 rolls.
Hang the front first, centred, so the design sits symmetrically on the breast.
Worked example: hall, stairs and landing
Stairwells break the usual arithmetic because the longest drop is so much longer than the rest. On a stairwell wall where the tallest drop measures 4.2m:
- Cut length: 4.2 + 0.06 = 4.26, rounded up to 4.32m (48cm repeat)
- Drops per roll: 10.05 ÷ 4.32 = 2.33, so 2 drops per roll
So a stairwell wall consumes paper roughly a third faster than a flat 2.4m wall. Measure the hall, the stairwell and the landing as three separate calculations and add them together. Averaging the height across all three will leave you short.
Quick reference: rolls for a single wall
Based on a 2.4m ceiling height and a design with a 24cm or 48cm repeat, both of which work out at 3 drops per roll. Add a spare roll to every figure.
| Wall width | Drops | Rolls |
|---|---|---|
| 2.0m | 5 | 2 |
| 3.0m | 7 | 3 |
| 4.0m | 9 | 3 |
| 5.0m | 11 | 4 |
| 6.0m | 13 | 5 |
Use it as a sense check, not as an order. Ceilings above 2.4m, or a repeat larger than 48cm, change the answer.
Rooms that need a different approach
- Sloping ceilings and loft rooms: measure the tallest point of each wall and use that for every drop on it. You will cut the slope in as you hang.
- Half walls and panelling: measure from the top of the panelling or dado rail, not the skirting. It often halves the roll count.
- Ceilings: measure the shorter dimension of the room as your drop length and treat the longer one as the width.
- Alcoves either side of a chimney breast: each alcove face is its own wall. Measure the back and both returns.
Order the whole job at once
Every Claret & Key order is printed to order, and a whole order is printed in a single run, so the colour is consistent from the first roll to the last. Ordering the spare with the job, rather than a fortnight later, is the surest way to know it will match.
If you do over-order, unopened rolls can be returned within 14 days, up to a maximum of five rolls, with return postage paid by you. Opened rolls cannot be returned, so work out your figures before you break the wrapping.
Check the design before you commit
Scale is fixed on our designs. What you can change is the colourway, on every design we make. Order an A3 sample in the colours you are considering and tape it to the wall for a few days before you order rolls. It is the cheapest possible way to avoid an eleven-roll mistake.
How many rolls of wallpaper do I need for one wall?
For a typical 2.4m-high wall, one roll covers three drops, which is about 1.44m of wall width. So a 3m wall needs 3 rolls and a 4m wall needs 3 rolls. Work it through properly with your own repeat before ordering.
How much wallpaper do I need for a 12ft × 12ft room?
A 12ft × 12ft room is 3.66m square, giving 14.6m of wall. That is 31 drops. At a 2.4m ceiling and 3 drops per roll, you need 11 rolls, plus a spare.
How much does one roll of wallpaper cover?
A roll is 4.82m² of paper. Realistically, on a 2.4m wall, expect it to cover around 3.5m² of wall once trimming and pattern matching are accounted for.
Do I deduct windows and doors?
Not for ordinary ones. Measure the full wall width and let the offcuts from above and below the opening do the work. Deduct only for very large openings.
What is a straight match?
It means the pattern lines up horizontally across the wall at the same height on every length, so you cut each drop at the same point in the design. It is simpler and less wasteful than an offset or half-drop match.
What if my ceiling is higher than 2.4m?
Do the arithmetic again with your own height. Above about 3.2m, a 48cm repeat drops you from 3 usable lengths per roll to 2, a jump that catches people out in period rooms and stairwells.
Is the roll estimator on your product pages exact?
No. The estimator on each product page gives you a quick, rough figure, and any calculation of this kind is a guide rather than an order. Measure your own walls, check the repeat on the design you have chosen, and order a spare roll.
