Inputs
Common: 520mm (UK), 530mm (EU), 700mm (wide).
Standard Euro roll: 10.05m.
Use 0 for plain / free match.
Typical: 10% (more for complex patterns).
Used to show net area and estimated spare area. Roll count is based on strip count.
Pattern repeats can increase the strip length needed. Always buy an extra roll for future repairs.
Results
Enter your room and roll details then click Calculate.
CACalifornia Building Code (Title 24)
References & Sources
Standards Cited
- American Single Roll — Standard American Single Roll Wallpaper Dimensions
Defines the standard American single roll as approximately 27 inches wide x 27 sq ft of coverage; wallpaper in North America is typically sold in double rolls - WIA/NGPP Guidelines — Wallcovering Installers Association / National Guild of Professional Paperhangers — Installation Guidelines
Industry guidance on pattern matching, wastage allowances, and strip calculation methods for North American wallpaper installation
Formulas Used
- Wall Area:
wallArea = roomPerimeter x wallHeight
Source: Standard geometry - Net Area:
netArea = wallArea - doorsWindowsArea
Source: WIA/NGPP installation guidelines - Effective Strip Height (with pattern):
stripHeight = ceil(wallHeight / patternRepeat) x patternRepeat
Source: WIA/NGPP installation guidelines — Each strip must start at a pattern repeat boundary for pattern matching - Strips per Roll:
stripsPerRoll = floor(rollLength / effectiveStripHeight)
Source: WIA/NGPP installation guidelines - Total Strips:
totalStrips = ceil(roomPerimeter / rollWidth)
Source: WIA/NGPP installation guidelines - Rolls with Wastage:
rolls = ceil(ceil(totalStrips / stripsPerRoll) x (1 + wastage% / 100))
Source: WIA/NGPP installation guidelines
Key Assumptions
- Standard American double roll: 27 inches (686 mm) wide x 27 sq ft usable coverage (approximately 20.5 ft / 6.25 m long) — US wallpaper industry standard
- US wallpaper is sold in double rolls but priced per single roll — US wallpaper industry convention
- Default 10% wastage for trimming and alignment — WIA/NGPP installation guidelines
- Pattern repeat of 0 indicates a plain wallpaper with no matching required — WIA/NGPP installation guidelines