Wallpaper Calculator – Simple, Accurate Roll Estimates
This wallpaper calculator helps you quickly work out how many wallpaper rolls you need for a room. Enter your room’s length, width, and wall height; we calculate the wall area (2 × (L + W) × H), subtract standard door and window areas, and factor in pattern repeat to estimate how many full-height strips you’ll get from each roll. It supports both metric and imperial units and common roll sizes.
How the Calculator Works
We use a strip-based method for accuracy. The effective strip length is your wall height rounded up to the next pattern repeat,
so patterned designs get the extra allowance they need. Strips per roll = floor(roll_length ÷ effective_strip_length).
Estimated coverage at your wall height = strips_per_roll × roll_width × wall_height
(pattern repeat reduces strips per roll).
Total rolls = ceil(strips_needed ÷ strips_per_roll).
Practical Tips
- Buy an extra roll if possible. Shade/batch numbers can vary; a spare ensures better future touch-ups.
- For bold patterns, a larger pattern repeat means more waste per strip—check the label before purchasing.
- Let rolls acclimate and follow the manufacturer’s paste-the-wall or paste-the-paper instructions.
- Store unused rolls flat and dry; label them with the room and date.
Related Interior Calculators
Wallpaper Calculator FAQs
How many wallpaper rolls do I need for a 10×12 room?
It depends on wall height, roll size, and pattern repeat. A 10×12 ft room with 8 ft walls often needs around 5–8 rolls, but larger repeats and taller walls reduce strips per roll and can increase rolls. Use this calculator with your exact dimensions for a more accurate estimate.
What if I have a large pattern repeat?
Large pattern repeats increase waste because each strip must be cut to align the design. This calculator rounds your wall height up to the next repeat to estimate an effective strip length, which reduces strips per roll and increases rolls needed.
Should I subtract windows and doors when calculating wallpaper?
Usually, yes—especially if you have large windows or multiple doors. This calculator subtracts typical opening areas by default to estimate net wall area.
How much extra wallpaper should I buy?
Many people buy one extra roll for future touch-ups and to ensure consistent dye lots. Patterned wallpapers and complex rooms may also require extra due to cutting waste.
What’s the difference between metric and imperial wallpaper roll sizes?
Metric rolls are commonly 53 cm wide and 10 m long, while imperial equivalents are often around 20.9–21 inches wide and about 33 ft long. Always check your wallpaper label for exact roll size.
Important Estimate Disclaimer
Results are provided for general planning and budgeting purposes only. Actual coverage may vary based on surface condition, layout complexity, waste allowance, and product specifications.
Refer to our Methodology and Data Sources for calculation assumptions.
Surface preparation, substrate irregularities, and installation methods may increase required material quantities.