Wallpaper Calculator | How Many Metres or Rolls of Wallpaper a Room Needs, With Pattern Repeat and Half-Drop Matching, Doors and Windows, Ceiling — Plus Paint Cans and a Room-Size Chart
The Wallpaper Calculator is a free tool for DIY decorating that works out how much wallpaper to buy from the size of your room. Enter the width, depth and ceiling height and it divides the wall width by the width each drop covers (for 92 cm Japanese vinyl wallpaper, the width minus the 2–3 cm overlap that is double-cut at the seam) to get the number of drops, and adds a trimming allowance to the ceiling height to get the length of each drop. It then tells you how many metres to order when wallpaper is sold by the metre, or how many rolls to buy for 50 m rolls or European rolls (52 cm × 10 m, 53 cm × 10.05 m). For patterned wallpaper, each drop is rounded up to a multiple of the pattern repeat, and half a repeat is added for half-drop patterns, so the waste from pattern matching is included. For doors and windows, only the drops that fit entirely within the opening are replaced with short pieces above and below, and those pieces are packed into the leftovers of each roll. It also handles the ceiling and a single feature (accent) wall, shows an unrolled wall diagram with the seams and drops per wall, and lets you copy the cutting list. If you are painting instead, it uses the same room to work out the litres needed from the number of coats and the spread rate, and suggests the combination of cans (0.7 L, 1.6 L and so on) with the least paint left over or the fewest cans. Includes a chart of how much wallpaper rooms from 4.5 to 20 tatami mats need.
Room size
Enter the inside wall widths in cm. Don't worry about skirting or coving — the height from floor to ceiling is fine.
Typically around 240 cm in Japanese homes
Doors and windows
Only drops that fit entirely within the opening are replaced with short pieces above and below. If in doubt, don't subtract — buying a little extra is safer.
Wallpaper type and pattern
Change the numbers below for wallpaper of any other width or roll length
Japanese wallpaper is overlapped 2–3 cm and double-cut. European wallpaper is butt-jointed: 0
Set to 0 for wallpaper sold by the metre
About 5 cm at the ceiling and 5 cm at the floor, 10 cm in total
For mistakes and re-hanging. 1–2 is typical
Amount needed
Length for the walls
37 m
Drops
16 drops
Area to cover
26.2 m²
| Where | Length of each | Drops |
|---|---|---|
| Full height | 250 cm | 13 drops |
| Above window | 50 cm | 1 drops |
| Below window | 100 cm | 1 drops |
| Spare | 250 cm | 1 drops |
1 drops that fit within doors and windows are replaced with short pieces above and below
ABOUT
About Wallpaper Calculator | How Many Metres or Rolls of Wallpaper a Room Needs, With Pattern Repeat and Half-Drop Matching, Doors and Windows, Ceiling — Plus Paint Cans and a Room-Size Chart
The Wallpaper Calculator is a free tool that works out how many metres of wallpaper — or how many rolls of European wallpaper — to buy from the room's width, depth and ceiling height. It divides the wall width by the width each drop covers (90 cm for 92 cm Japanese wallpaper after the 2 cm overlap) to get the number of drops, and adds a 10 cm trimming allowance to the ceiling height for the length of each drop. Patterned wallpaper is rounded up to a multiple of the pattern repeat, with half a repeat added for half-drop patterns, so matching waste is included. It also counts the short pieces above doors and above and below windows, the ceiling and spare drops. For painting, it works out the litres needed and the best mix of cans, and it has a chart by room size.
How to use Wallpaper Calculator | How Many Metres or Rolls of Wallpaper a Room Needs, With Pattern Repeat and Half-Drop Matching, Doors and Windows, Ceiling — Plus Paint Cans and a Room-Size Chart
- 1In “Wallpaper needed”, enter the room width, depth and ceiling height in cm (switch to “One wall at a time” for a single wall)
- 2Enter the width and height of each door and window (and the height from the floor to the bottom of each window). Tick the box if you are papering the ceiling too
- 3Choose the wallpaper (92 cm Japanese wallpaper, 52 cm × 10 m European rolls and so on) and, if it is patterned, the pattern match and repeat length
- 4Check the metres or rolls needed, the number of drops and the length of each, and the cutting list, then copy the result
- 5If you are painting, open “Paint cans”, enter the number of coats and the spread rate, and see the litres needed and the combination of cans
- 6For a rough figure before measuring, check the chart for 6- or 8-mat rooms in “Chart by room size”
Great for
- Decide how many metres of pre-pasted wallpaper to order before redecorating a 6-mat bedroom yourself
- Find how many rolls of European or non-woven wallpaper to buy, including pattern repeat and half-drop matching
- Work out the length needed to paper a single feature wall in a different colour or pattern
- Get separate wall and ceiling quantities when redecorating a whole room
- Check whether the short pieces below windows and above doors can come out of roll leftovers
- Decide which mix of 0.7 L, 1.6 L, 3 L and 7 L cans to buy when painting instead of wallpapering
- Compare a contractor's quote with the chart by room size
Good to know
- Most Japanese vinyl wallpaper is 92 cm wide. Seams are overlapped by 2–3 cm and both layers are cut together (double-cutting), so each drop is counted as covering about 90 cm. European and non-woven wallpaper is butted at the seams, so set the overlap to 0.
- Each drop is the ceiling height plus a trimming allowance — about 5 cm at the top and 5 cm at the bottom, 10 cm in total. Measuring from floor to ceiling is enough even if some of it is hidden behind skirting or coving.
- Patterned wallpaper must line up with the next drop, so each drop is rounded up to a multiple of the pattern repeat. For a half-drop pattern (offset by half a repeat on the next drop), half a repeat is added on average. The bigger the repeat, the more waste.
- For doors and windows, only the drops that fit entirely within the opening are replaced with short pieces above and below. Drops that overlap the edges of the opening are counted at full height, so the result is rarely an underestimate.
- For wallpaper sold in rolls, the drops are packed into rolls longest first. Different batches can vary slightly in colour, so buy everything at once from the same batch and add one or two spare drops.
- The ceiling is assumed to have no pattern matching; strips run across the shorter side and are cut to the longer side plus the allowance.
- Paint is calculated as area × coats ÷ spread rate (m² per litre), plus waste left in the roller and tray. Spread rates differ by product, so enter the coverage printed on the tin.
- Everything is calculated in your browser and your measurements are stored only on this device. The result is a guide to how much to buy and can change with the shape of the room (columns, beams, bay windows, sloped ceilings).
Questions this tool answers
Use Wallpaper Calculator | How Many Metres or Rolls of Wallpaper a Room Needs, With Pattern Repeat and Half-Drop Matching, Doors and Windows, Ceiling — Plus Paint Cans and a Room-Size Chart for searches like these:
- How many metres of wallpaper do I need for my room?
- How many rolls of wallpaper should I order?
- How do I calculate wallpaper with a pattern repeat?
- How many rolls do I need for a half-drop wallpaper?
- How much wallpaper do I need for a feature wall?
- How much wallpaper does a ceiling need?
- How many cans of paint should I buy?
- How much less wallpaper do I need for doors and windows?
FAQ
- How many metres of wallpaper does a 6-mat room need?
- With a 240 cm ceiling and 92 cm wide wallpaper, about 35 m (14 drops × 2.5 m) for the four walls. That is for a standard Edo-ma 6-mat room (about 2.64 m × 3.52 m), without subtracting doors or windows. The ceiling needs about 11 m more. Add one or two spare drops (2.5–5 m) to be safe.
- How much wallpaper does an 8-mat room need?
- With a 240 cm ceiling and 92 cm wide wallpaper, about 40 m (16 drops) for the walls and about 15 m for the ceiling. A 10-mat room needs about 45 m for the walls and a 12-mat room about 50 m. If your ceiling is 250 cm or higher, each drop gets longer, so enter your ceiling height in the calculator.
- How many 52 cm × 10 m rolls do I need for a 6-mat room?
- For plain wallpaper with a 240 cm ceiling, 26 drops at 4 drops per roll: 7 rolls. With a 64 cm pattern repeat each drop grows to 256 cm (288 cm for a half drop), so you only get 3 drops per roll and need 9 rolls.
- What are pattern repeat and half drop?
- The pattern repeat is the vertical distance before the design repeats. With a straight match the pattern lines up at the same height on the next drop; with a half drop it is offset by half a repeat. Both waste some paper to line up the design, so each drop is rounded up to a multiple of the repeat, and half a repeat is added for a half drop.
- How much wallpaper do I need for one feature wall?
- For a wall 360 cm wide with a 240 cm ceiling, 4 drops of 92 cm wallpaper: 2.5 m × 4 = 10 m. Switch to “One wall at a time” and enter just that wall's width.
- Can I subtract doors and windows?
- Only the drops that fit entirely within the opening. For a 165 cm wide window, one 90 cm drop becomes short pieces above and below the window. Drops across the edges of the window are usually cut full height, so this calculator replaces only the drops that fit inside the opening to avoid subtracting too much.
- How many litres of paint do I need for the walls of a 6-mat room?
- About 8.1 L for two coats on the four walls (about 29.6 m²) with paint that covers 8 m² per litre and 10% waste. With 0.7 L, 1.6 L, 3 L and 7 L cans, that is either 7 L + 1.6 L (2 cans) or 3 L × 2 + 1.6 L + 0.7 L (0.2 L left over).
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