Wallpaper Calculator
Estimate whole wallpaper rolls using wall widths, wall height, roll size, trim and pattern repeat.
Why strip planning helps
Pattern repeat can change roll yield
Wallpaper is installed in vertical strips, so area alone can hide waste. DIYSum rounds each wall to whole strips and rounds the drop length up to the pattern repeat you enter.
Rolls = required strips ÷ strips per roll
What if my walls have different heights?
This version assumes one common wall height. For rooms with materially different heights, calculate those groups separately and add the roll totals conservatively.
Why not subtract every window and door?
Wallpaper around openings still uses portions of full strips, especially with a pattern match. A strip-based estimate is usually safer than simple square-foot subtraction.
Real-world project example
How many wallpaper rolls for a 12 × 12 ft room?
A 12 × 12 ft room has 48 linear feet of wall perimeter. With 8 ft walls, that is 384 sq ft gross wall area before openings. Roll purchases must account for usable strip length, wallpaper width, vertical pattern repeat, trimming and package coverage; dividing 384 by advertised roll square footage alone can underestimate how many rolls you need.
Before you buy materials
Use the calculator’s strip and repeat inputs and match the exact manufacturer roll size. Doors, windows, pattern matching and batch/dye lot can change a realistic order.
Adjust the measurements, waste allowance and purchase options in the calculator above to estimate your own project; examples are for planning only.