Formula
Wall area = total wall width × wall height − opening area. Planning area = wall area × (1 + waste percent ÷ 100). Roll coverage = roll width × roll length. Rolls needed = ceiling(planning area ÷ roll coverage).
Construction & Home
Wallpaper Calculator
Estimate wallpaper rolls from wall width, wall height, roll size, repeat allowance and openings, with the formula and printable room note kept visible.
Calculator
Working calculator
Live result6 rolls26.8 m² measured · 30.82 m² with 15% allowance · 5.3 m²/roll · 210.00 material estimate
Formula used
Wall area = total wall width × wall height − opening area. Planning area = wall area × (1 + waste percent ÷ 100). Roll coverage = roll width × roll length. Rolls needed = ceiling(planning area ÷ roll coverage).
This is the method behind the answer, so the result can be checked rather than simply trusted.Visual grid
This result measures part of the space you live in
Length, area, volume and material estimates are grid problems too: measure the space, account for edges and allowances, then turn the pattern into a number you can use.
Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars
Measured output6 rolls
Space calculations turn a real surface, room, run or volume into cells, edges and allowances that can be quoted, ordered or checked.
CalculationTime
Wallpaper Calculation Report
6 rolls26.8 m² measured · 30.82 m² with 15% allowance · 5.3 m²/roll · 210.00 material estimate
Inputs
- Total wall width
- 12 m
- Wall height
- 2.4 m
- Doors/windows to subtract
- 2 m²
- Roll width
- 0.53 m
- Roll length
- 10 m
- Pattern/waste allowance
- 15 %
- Optional price per roll
- 35 currency/roll
Method
Wall area = total wall width × wall height − opening area. Planning area = wall area × (1 + waste percent ÷ 100). Roll coverage = roll width × roll length. Rolls needed = ceiling(planning area ÷ roll coverage).
- For 12 m total wall width at 2.4 m high, gross wall area is 28.8 m². Subtract 2 m² of openings to get 26.8 m². Add 15% allowance: 26.8 × 1.15 = 30.82 m². A 0.53 m × 10 m roll covers 5.3 m², so 30.82 ÷ 5.3 = 5.82 and the order estimate rounds up to 6 rolls.
Assumptions
- Walls are treated as a combined rectangular area; split unusual rooms into simpler wall sections before adding the widths.
- Roll width, roll length and pattern allowance must come from the exact wallpaper product where possible.
- The calculator rounds rolls up to whole rolls because partial rolls cannot usually be ordered as exact area.
- Pattern repeat, batch matching, damaged strips, stairs, alcoves and professional hanging method can change the real order quantity.
Notes
Use this space on the printed report for client, supplier, classroom, job-location, measurement, quote or approval notes.
Worked example
For 12 m total wall width at 2.4 m high, gross wall area is 28.8 m². Subtract 2 m² of openings to get 26.8 m². Add 15% allowance: 26.8 × 1.15 = 30.82 m². A 0.53 m × 10 m roll covers 5.3 m², so 30.82 ÷ 5.3 = 5.82 and the order estimate rounds up to 6 rolls.
Professional note
Master’s Tip: keep the product batch, roll width, roll length and pattern repeat beside the estimate. Wallpaper mistakes are often not arithmetic mistakes; they come from pattern matching, dye-lot changes, awkward offcuts and under-ordering one extra repair roll.
Regional and unit assumptions
Standard or basis: rectangular wall-area arithmetic using metric dimensions and whole-roll rounding. No manufacturer coverage guarantee, decorator quote, fire rating, paste specification or building-code approval is implied.
Assumptions and limitations
- Walls are treated as a combined rectangular area; split unusual rooms into simpler wall sections before adding the widths.
- Roll width, roll length and pattern allowance must come from the exact wallpaper product where possible.
- The calculator rounds rolls up to whole rolls because partial rolls cannot usually be ordered as exact area.
- Pattern repeat, batch matching, damaged strips, stairs, alcoves and professional hanging method can change the real order quantity.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
Wall area = total wall width × wall height − opening area. Planning area = wall area × (1 + waste percent ÷ 100). Roll coverage = roll width × roll length. Rolls needed = ceiling(planning area ÷ roll coverage).
Standard or basis
Standard or basis: rectangular wall-area arithmetic using metric dimensions and whole-roll rounding. No manufacturer coverage guarantee, decorator quote, fire rating, paste specification or building-code approval is implied.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: keep the product batch, roll width, roll length and pattern repeat beside the estimate. Wallpaper mistakes are often not arithmetic mistakes; they come from pattern matching, dye-lot changes, awkward offcuts and under-ordering one extra repair roll.
Related calculators
Questions
How do I calculate how many rolls of wallpaper I need?
Multiply total wall width by wall height, subtract significant doors and windows, add a waste or pattern allowance, then divide by the coverage area of one roll and round up to a whole roll.
Should I subtract windows and doors for wallpaper?
Subtract large openings when they materially reduce wall area, but keep a practical allowance for trimming, offcuts and pattern matching. Very small openings may not reduce the order quantity.
What waste allowance should I use for wallpaper?
A simple room may use about 10% extra, while patterned wallpaper, awkward walls, stairs or novice installation can justify 15–25% or more. Use the allowance field to make that judgement visible.
Why does the calculator round up rolls?
Wallpaper is bought in whole rolls. Even if the area calculation says 5.1 rolls, the practical order estimate is 6 rolls before batch matching and supplier advice.
Does this handle pattern repeat exactly?
It handles pattern repeat as a percentage allowance, not a strip-by-strip layout. For expensive patterned paper, confirm the repeat, drop match and roll batch with the supplier or decorator.
Calculation note
Wallpaper estimating connects simple area arithmetic with a practical ordering problem. A wall can be measured in square metres, but wallpaper is bought as rolls with fixed width, length, pattern direction and batch colour. The printable report keeps the room dimensions, roll assumptions, allowance and notes together so the estimate can survive a supplier call or decorator quote.
Area is only the starting point
The calculator first treats the room as measured wall area: total wall width multiplied by wall height, minus significant openings. That gives a clean mathematical base before the order allowance is added.
Roll coverage turns area into a purchase quantity
Wallpaper rolls have a fixed width and length. Multiplying those values gives a nominal roll coverage area, but real usable coverage can be lower when patterns must align or strips need trimming.
Pattern repeat belongs in the paper trail
A plain wallpaper and a large drop-match pattern can have very different waste even in the same room. The report keeps the allowance visible instead of hiding it inside a single roll number.
Sources and further readingNIST: Metric/SI units and measurement resourcesWallcoverings Association: Wallcovering resources