How to Measure a Room for Wallpaper
Quick answer: add up height × width for every wall, subtract ~21 sq ft per door and 12–15 sq ft per window, add 15–25% for pattern repeat, and divide by 56 sq ft per double roll. A 10×10 room needs about 6–7 double rolls.
- Measure every wall
- Subtract doors and windows
- Pattern repeat: the real waste
- Roll sizes and coverage
- Worked example: 10×10 room
- Common mistakes
- FAQ
Measure every wall
Wallpaper is ordered in rolls, so the measurement job is wall area: height × width for each wall, added together. A 10×10 room with 8 ft walls has 4 walls × 80 sq ft = 320 sq ft. Measure wall by wall — don't assume all four are identical; door widths and window placements vary.
Subtract doors and windows
Take off about 21 sq ft per door (3×7 ft) and 12–15 sq ft per window. Subtract them from the total before waste — papering over openings wastes rolls. A 10×10 room with one door and two windows sheds about 51 sq ft, dropping 320 to ~269 sq ft.
Pattern repeat: the real waste
Plain wallpaper wastes little. Patterned wallpaper must line up from strip to strip, and each strip may discard a chunk of the roll to match. A 20-inch repeat on an 8 ft (96 in) wall loses roughly one drop per roll. Budget 15% for small patterns, 20–25% for large florals and geometrics. This is the number that most DIY estimates get wrong.
Roll sizes and coverage
US wallpaper is sold as single rolls (28 sq ft) and double rolls (56 sq ft). Coverage is quoted in double rolls because most wallpaper comes pre-packaged that way. After an average 20% pattern loss, plan on about 45 sq ft of usable wall per double roll for patterned paper, or the full 56 for plain.
Worked example: a 10×10 room with 8 ft walls
- Wall area = 4 × (10 × 8) = 320 sq ft
- Minus 1 door (21) + 2 windows (28) = 271 sq ft
- Add 20% pattern waste = 325 sq ft
- ÷ 56 sq ft per double roll = 5.8 → 6–7 double rolls
Common mistakes
- Forgetting pattern waste. Ordering plain-paper quantities for a big floral = running out two strips from the end.
- Not matching dye lots. Rolls from different batches shift in shade. Order all at once, and check the batch number on every roll.
- Measuring around openings instead of subtracting. Windows and doors don't get paper — subtract them and use the cutoffs for short sections like above doors.
- Ignoring the drop-match rule. With a pattern, every strip starts at the same repeat point — buy enough to account for the alignment loss, not just the square footage.
FAQ
Measure each wall's height and width, multiply for area, add the walls together, subtract doors (about 21 sq ft) and windows (12–15 sq ft), then add 15–25% waste for pattern repeat and cuts. A 10×10 room needs about 6–7 double rolls.
About 6–7 double rolls for a 10×10 room with 8 ft walls. The walls total about 320 sq ft; after doors, windows and pattern waste you land near 280–300 sq ft.
About 8–9 double rolls for a 12×12 room with 8 ft walls. Wall area is 384 sq ft; after openings and 20% pattern waste that's roughly 340–360 sq ft, or 6.5–7 double rolls before rounding up.
Add 15–25% for a pattern that must line up. A 20-inch repeat on an 8 ft wall wastes about one drop per roll. Large florals can add 25% or more.
A standard US double roll covers about 56 sq ft of wall before pattern waste. After an average 20% pattern loss, a double roll effectively covers roughly 45 sq ft.