How many rolls of wallpaper do I need?

Count the drops, not just the area. Divide the length of wall by the roll's width for the number of drops, work out how many drops of your wall's height one roll gives, and divide. A 4 × 3.5 m room has 15 m of wall, so 29 drops of 53 cm paper. With 2.4 m walls, a 10 cm trim and a 53 cm straight repeat, each drop takes 2.65 m and a 10.05 m roll gives three, so you need 10 rolls. The area method (wall area ÷ roll area) says 7, because it assumes every offcut gets used.

How much does one roll of wallpaper cover?

On paper, its width times its length: a 10.05 m × 53 cm Euro roll is 5.33 m², Sanderson's 10.05 m × 52 cm roll 5.23 m² (56.3 sq ft), and a US double roll of 20.5 in × 33 ft about 56 sq ft. On the wall it covers less, because every drop is cut to the wall's height plus trim and pattern, and the rest of the roll is an offcut. That is why the drop count is higher than the area method.

What does the pattern repeat do to the amount?

Every drop has to start at the same point in the pattern (or, for a half drop, alternate between two points), so each drop is rounded up to the pattern. On a 2.4 m wall with 10 cm trim, a free match drop is 2.5 m and a 10.05 m roll gives four; with a 53 cm straight repeat each drop is 2.65 m and the roll gives three.

What is the difference between a straight match and a half drop?

In a straight match the pattern continues straight across from one drop to the next, at the same height. In a half drop it continues half a repeat lower, so the design runs diagonally (Sanderson and Cole & Son describe it this way). Offset match is the general case: the next drop continues at a stated distance, such as a third of the repeat. Free or random match has no pattern to line up.

Should I take off doors and windows?

Only a little. Morris & Co's calculator makes no reduction for doors and windows, and Brewster suggests deducting one bolt for every four ordinary doors or windows. This calculator shortens only the strips that are certain to lie wholly over an opening, and still counts the pieces above a door and above and below a window, cut from the offcuts where they fit.

What is a double roll of wallpaper?

In the US wallpaper is usually priced by the single roll but sold two single rolls in one bolt, the double roll. York's double roll is 27 in × 27 ft, two single rolls of 27 in × 13.5 ft; Brewster's bolt is 20.5 in × 33 ft, about 56 sq ft. Pick the size from the roll menu and the calculator counts in double rolls.

How much wallpaper paste do I need?

It says on the packet. Graham & Brown's Premium Wallpaper Adhesive hangs up to eight rolls, a tube of Farrow & Ball paste up to five of its rolls, Sanderson rates its ready-mixed tub for five standard rolls or four wide ones, and Roman PRO-880 covers up to 330 sq ft a gallon, counted here on the paper you cut and hang, not the bare wall. Pick one, or type what your paste hangs, and the calculator adds it to the list. Pre-pasted and peel-and-stick papers need none.

Why do batch numbers matter?

Rolls printed together carry the same batch number, and rolls from different batches can differ slightly in colour. Cole & Son say rolls from the same batch should be hung together, and Laura Ashley that it doesn't record which batch went to which order. Buy every roll you need at once, plus a spare if you want one for repairs, and check the numbers match before you cut.

Wallpaper Calculator: How Many Rolls Do I Need?

How to use the wallpaper calculator

Pick what you are papering. Rooms takes each room's length, width and wall height, and papers all the way round. Walls takes walls one at a time: a feature wall, a chimney breast, or the walls of a room you only paper in part. Mural is for a picture sold as one piece or made to measure.
Measure. Height from the top of the skirting board to the ceiling or coving, width along the wall. Type feet and inches as 8'6" or metres as 2.4; other units work too (240 cm, 102 in).
Set the doors and windows. Each room starts with one door and one window; change the counts with − and +, and the sizes to yours. For a window, the sill is the height from the floor to the bottom of the window.
Pick the roll. The menu has the standard sizes (the 10.05 m × 53 cm Euro roll, US double rolls, wide widths, peel and stick) and each maker's own roll. If yours isn't there, type its width and length from the label.
Set the pattern. The repeat and the match type are on the roll label and the product page: free match, straight, half drop, or offset with its distance.

The big figure is the rolls to buy. Under it you see the working: how long each drop is, how many one roll gives, and what the area method would say. The table lists each room or wall. Everything stays in your browser, and your rooms are still here when you come back. Share result makes a link that opens the same calculation for someone else, and Copy shopping list puts it on your clipboard.

Why the calculator counts drops

Wallpaper is hung in vertical strips called drops, each cut from the roll to the wall's height plus a trim at the top and bottom. What is left at the end of a roll after the last whole drop is an offcut, and offcuts only help over doors and windows. So the honest question is how many drops the room needs and how many drops one roll gives, which is how Cole & Son and Sanderson tell you to work it out, and what this calculator does:

Drops across the walls = length of wall ÷ roll width, rounded up. A room is one run round all four walls: the strip that turns a corner is cut, and its offcut starts the next wall.
Drop length = wall height + trim (Morris & Co allow 10 cm, or 4 in), rounded up to the pattern: whole repeats for a straight match, a repeat plus the offset for a half drop or offset match.
Drops per roll = roll length ÷ drop length, rounded down.
Rolls = every drop and every short piece over the doors and windows, packed into rolls, longest first.

A 4 × 3.5 m room with 2.4 m walls has 15 m of wall: 29 drops of 53 cm paper. With a 53 cm straight repeat each drop is 2.65 m, a 10.05 m roll gives three, and the room takes 10 rolls. The area method, 33 m² of wall over 5.33 m² a roll, says 7. The calculator shows both, so you can see how much the pattern costs you.

Doors, windows and the offcuts

Where the strips fall is only known when you hang them, so the calculator shortens only the strips that are sure to lie wholly over an opening: one strip over a 1.2 m window when the roll is 53 cm wide, none over a 76 cm door. Each of those needs a piece above the opening, and a window a piece below it too; they come out of the offcuts at the end of each roll where they fit. Makers are more cautious still: Morris & Co's calculator takes nothing off for doors and windows, and Brewster suggests taking off one bolt for every four ordinary doors or windows.

Rolls, paste and batch numbers

UK and European rolls are about 10 m long and 52 or 53 cm wide: Farrow & Ball's are 10 m × 53 cm, Sanderson's and Morris & Co's 10.05 m × 52 cm, Graham & Brown's and Cole & Son's 10 m × 52 cm. Wide-width papers such as Morris & Co's 68.6 cm need fewer drops. In the US, paper is sold in double rolls: Brewster's bolt is 20.5 in × 33 ft, York's 27 in × 27 ft. Peel-and-stick rolls are shorter; Tempaper's are 20.5 in × 16.5 ft.

Pick a paste and the calculator counts the packs from what the maker says one pack hangs. Tick Add a spare roll if you want one for mistakes and later repairs, and add prices to see the cost. Order every roll at once: a batch printed later can differ slightly in colour, so check that the batch numbers on the labels match before you cut the first drop.

Tips

Planning the room first? Build it in the 3D room planner: the calculator offers to add that room with its doors and windows.
Painting the ceiling and woodwork? The paint calculator works out the paint for the same room, and the flooring calculator the floor.
Hanging a large pattern on one wall? Switch to Walls and compare a half drop with a straight match of the same repeat: the difference can be a whole roll.

Sources, checked September 2026: Cole & Son, FAQ; Sanderson, wallpaper FAQs; Morris & Co, wallpaper quantity calculator; Farrow & Ball, wallpaper FAQ; Brewster, wallpaper calculator; York, Gracie wallpaper; Tempaper, Cherry Bomb; Erfurt, 2024 product range.

How to use the wallpaper calculator

Why the calculator counts drops

Doors, windows and the offcuts

Rolls, paste and batch numbers

Tips

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