Sloped Ceilings
How Much Wallpaper Do You Need for a Sloped Ceiling?
Loft conversions, attic bedrooms and dormer rooms almost always have at least one sloped wall, and a standard "width × height" wallpaper formula doesn't know what to do with an angle. Ask a generic online calculator and it'll want a single flat height for the whole room, which is exactly the number a sloped wall doesn't have. Here's what actually changes when a wall isn't a rectangle, and how to still land on the right roll count.
Open the Wallpaper PlannerMeasure to the tallest point, not the average
It's tempting to measure a sloped wall at its midpoint and treat that as the height, but every strip on that wall still has to be cut long enough to reach the tallest point where it starts — the slope just means you trim the excess off the short end afterwards. Measuring to the average height under-orders every single strip on that wall.
Treat the slope as its own wall, not part of the ceiling
A sloped section of a wall (as opposed to a flat, horizontal ceiling) still hangs like a wall — vertical strips, seams running floor to slope. Keep it as a separate wall in your measurements rather than folding it into the ceiling area or the flat wall below it, the same way the planner treats every wall in a room individually.
Pattern repeat shows up faster on an angle
Because each strip on a sloped wall is cut to a different final length (the angle trims a different amount off each one), a patterned repeat has to stay aligned across strips that are no longer all the same length. This is exactly where hand-measuring a slope goes wrong — the strip-by-strip cutting plan handles it automatically.
Order one buffer roll for angled cuts
Angled cuts waste more offcut than a straight horizontal trim, since the cut runs diagonally across the strip instead of straight across it. A single extra roll on a sloped-wall job is cheap insurance against running short mid-cut, especially if the dye lot might not be available for a same-batch reorder.
Dormer cheeks and window reveals count as separate small walls
A dormer window usually has two short angled 'cheek' walls either side of it, plus the reveal itself — each one is a small, oddly-shaped wall in its own right, not part of the main sloped wall's total. Measure and cut each one separately rather than trying to fold their area into the bigger slope, or the numbers for both will be off. On a busy pattern, matching a cheek wall to the main slope next to it is worth planning for deliberately rather than hoping it lines up by chance.
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See plans & pricingCommon questions
Do I measure a sloped ceiling the same as a sloped wall?
A true sloped ceiling (overhead, walked under) is usually left painted rather than papered in most jobs — what people mean by 'sloped ceiling wallpaper' is almost always the angled wall section of a loft or dormer room, which hangs like any other vertical wall, just cut to the slope.
Can the planner handle a room with a sloped wall?
Yes — the room editor includes a sloped-ceiling template alongside rectangle, gable, stairwell and stepped-room templates, plus a free-form point-by-point outline for anything more irregular.
Does a steeper slope waste more wallpaper than a shallow one?
Generally yes — a steeper angle trims more off each strip, and that lost offcut is rarely long enough to reuse elsewhere. It's not usually enough to change the roll count by itself, but it's part of why a buffer roll is worth ordering on any sloped-wall job.
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