Wallpaper Calculator
Enter room dimensions, doors/windows and roll size to estimate wallpaper rolls needed and total cost, with pattern-repeat (matching) adjustment. Essential for home decorating.
Input Data
Results
At a glance:The wallpaper calculator is based on "wall area ÷ roll coverage". Gross wall area = room perimeter × height; deduct doors/windows. If the wallpaper has a pattern repeat, each strip's effective height is rounded up to a multiple of the repeat, scaling the net area; rolls needed = ⌈net area ÷ (roll width × length)⌉.
Formula
Gross area G = (length + width) × 2 × height
Door area = doors × door height × door width
Window area = windows × window height × window width
Adjusted height H = ⌈height ÷ repeat⌉ × repeat (no repeat: H = height)
Net area = (G − doors − windows) ÷ height × H
Rolls N = ⌈net area ÷ (roll width × roll length)⌉
Example: 5×4×2.5 m, 0.53 m × 10 m roll → about 7 rolls
$$G = 2(L+W) \cdot h$$$$H = \left\lceil \frac{h}{p} \right\rceil \cdot p$$$$A_{net} = \frac{G - A_d - A_w}{h} \cdot H$$$$N = \left\lceil \frac{A_{net}}{w_r \cdot l_r} \right\rceil$$How to Use
- Enter room length, width and height (m).
- Enter door and window count and size (0 if none).
- Enter roll length and width.
- Enter pattern repeat if any; 0 for plain.
- Enter price per roll to estimate cost.
- The tool outputs areas, rolls needed and total cost.
Case Studies
Bedroom wallpaper
Bedroom 4×3 m, 2.5 m high, one door (2×0.9) and one window (1.2×0.9).
Gross wall 35 m², net about 32.4 m² after deduction.
Standard 0.53 m × 10 m roll needs about 7 rolls; order 8 with waste.
Living room with pattern
5×4 m, 2.7 m high, pattern repeat 64 cm.
Repeat raises effective height, so order 1–2 extra rolls.
FAQ
Why order extra rolls with pattern?
Pattern repeat needs alignment, raising effective strip height and waste; buy 1–2 extra rolls and keep the batch number for patches.
How to handle no-match plain paper?
Set pattern repeat to 0; the calculator uses the room height directly without repeat scaling, less waste.
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References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.