Free tool for a sloped or stairwell wall, where one height does not fit every strip. It works out each strip separately, using the high side of each strip, so a middle strip is never cut short.
Each strip's finished height is interpolated in a straight line from the low end to the high end. For strip i out of n strips, the height used is the high side of that strip, not its centre, so the strip is long enough at both edges. Add the trimming allowance, then round up to a whole pattern repeat if there is one. The difference between the rounded cut and the raw length is the repeat waste for that strip. Add all cuts for the total length, and divide by the roll length, rounded up, for the rolls needed.
Low end 250 cm, high end 410 cm, 7 strips, 10 cm trimming allowance and a 32 cm repeat give cuts of 288, 320, 352, 352, 384, 416 and 448 cm. The total cut length is 25.60 m, including 1.00 m of repeat waste, so 3 rolls of 1000 cm are needed. Notice two middle strips come out the same after repeat rounding; that is normal and is not a mistake.
This is an estimate for planning and ordering, not a hanging instruction for a specific paper. Check the paper's width, repeat, pattern direction and the supplier's instructions, and measure both ends and the slope in person, because a stairwell is rarely a perfect straight slope. Allow extra paper for matching at doors, windows and corners, which this calculator does not cover.
Why not use one average height? One height would cut the tall strips short and waste paper on the short strips. A sloped wall needs a different length for each strip.
Why use the high side of each strip? Using the centre height would make middle strips too short at their tall edge. The high side keeps every strip long enough, with the extra trimmed off on site.
What if my paper is plain? Enter 0 for the pattern repeat. The cut is then just the interpolated height plus the trimming allowance, and the repeat waste is zero.
How many rolls should I actually buy? The calculator rounds up to whole rolls. For a large or expensive paper, buy one extra roll for matching mistakes and future repairs, and check that all rolls are from the same batch.
About this tool: a free, single-page calculator. It runs entirely in your browser and does not save, upload or send your measurements. No sign-up and no payment are needed to use it.
Privacy: this page does not collect your measurements. Any advertising on this page, if approved, is served by Google AdSense; this page itself does not ask for your name, address or payment details.