Wallpaper Calculator
Work out how many rolls of wallpaper a room needs, from its dimensions, doors, windows, and the roll size you're buying.
Room dimensions
Roll & waste
Before you buy
- A large pattern repeat wastes more per cut than a plain or small-repeat design — increase the buffer for bold, large-scale patterns.
- Buy one roll more than the calculated minimum, from the same batch/dye lot — rolls from a different production run can differ slightly in shade, and it's far easier to buy one extra now than to hunt down a matching batch later.
- This is an area-based estimate, not a strip-by-strip cutting plan — real usage is measured in whole vertical strips, so actual consumption can round up to a partial roll more than the pure area ratio suggests.
How this is calculated
Wall area is the room's perimeter times its height (2 × (length + width) × height), minus a standard deduction for each door (≈1.6 m²) and window (≈1.5 m²) — the same deductions used in the paint calculator. A waste buffer is added on top for trimming and pattern matching, and the result is divided by one roll's coverage area (roll width × roll length), rounded up — partial rolls aren't sold. This is an area-based approximation: real wallpapering is done in floor-to-ceiling strips, so it's worth leaning toward a larger buffer for a patterned roll.
Common questions
Why is this an estimate rather than an exact number?
Because real wallpaper is hung as whole vertical strips cut to ceiling height, not painted on by area. A roll's usable length rarely divides evenly into whole strips, and a repeating pattern needs extra length per strip to line up — both waste more than a pure area calculation accounts for. The waste buffer exists to cover that gap; a bigger, bolder pattern repeat deserves a bigger buffer.
Which roll size should I choose?
Whatever your chosen wallpaper is actually sold in — check the label or product page. Standard (0.53m wide) is the most common width; wide/metric rolls (1.06m) cover the same area in half as many rolls, which usually means fewer seams too. Both preset buttons just fill in the width/length fields — you can always type your product's exact size instead.
Does this include the ceiling?
No — this covers walls only, the same scope as the paint calculator. Ceiling wallpaper (much less common) would need its own area calculated separately.
Part of Home Improvement Calculators