THE TOOLKIT / 02
Wallpaper calculator
Count complete wallpaper strips for a single rectangular wall, including trimming and straight-match pattern repeats.
Free to use · No account needed · Imperial & metricFor one wall with random or straight-match wallpaper. Assumes each strip starts on a usable pattern position. Does not model first-roll alignment loss, half-drop, offset or A/B patterns, murals, openings or reusable offcuts. Check the supplier’s roll calculator before ordering.
THE MATH, WITHOUT THE MYSTERY
How this estimate works
Strips = round up(wall width ÷ roll width). Add total trim to wall height; for straight matches, round that length up to a whole pattern repeat. Strips per roll = round down(roll length ÷ cut length). Rolls = round up(strips ÷ strips per roll) + extra rolls.
A worked example
A 12 ft wide wall needs seven strips from a 21 in wide roll. At an 8 ft height plus 4 in total trim, a 33 ft roll supplies three complete strips. Seven strips need three rolls. A 24 in straight-match repeat rounds each cut to 10 ft; this example still needs three rolls before optional spares.
Read the complete calculation noteA FEW USEFUL ANSWERS
Before you buy
Can I use this for a half-drop pattern?
No. Half-drop, offset and alternating A/B designs need a different cutting plan. Follow the manufacturer’s calculator or ask your supplier to check the layout.
Should I subtract windows and doors?
This tool plans full-height strips across the whole wall and does not deduct openings. A real cutting layout may reuse offcuts around openings; an area-only deduction can underestimate the full strips you need.
Is a double roll two of the rolls in this result?
Enter the width and full usable length of the actual package you buy, and enter its price. Marketing terms such as single roll and double roll are not used in this calculation.