Wallpaper Calculator
Rolls = (wall area × 1.1) ÷ roll coverage
How Wallpaper Calculations Work
Wallpaper quantity depends on wall surface area and how much each roll covers after pattern matching. Wall area = 2 × (length + width) × height. A 12 ft × 12 ft room with 8 ft ceilings has 384 sq ft of gross wall. Subtract one door (21 sq ft) and two windows (24 sq ft) for 339 sq ft net.
Standard rolls are 20.5 in wide (1.71 ft) and 33 ft long, covering about 56 sq ft per roll with no pattern repeat. With a 24 in pattern repeat, each cut strip wastes partial length to align the pattern — effective roll length drops to the largest multiple of the repeat fitting in 33 ft. At 24 in repeat, only one 24 in segment fits cleanly per strip, reducing usable roll length significantly.
Add 10% waste for trimming and mismatches: 339 × 1.10 = 373 sq ft needed. Without pattern repeat: 373 ÷ 56 = 6.66 rolls — buy 7 rolls. Bold patterns with large repeats may need 15–20% extra. Peel-and-stick and pre-pasted papers vary in roll dimensions — always check the label.
Prep matters as much as quantity. Walls must be smooth, primed, and sized. Remove old paper with steam or scoring tools. Book pasted paper per manufacturer instructions (typically 3–5 minutes) before hanging. Start from a plumb line, not the corner — corners are rarely perfectly vertical.
| Room | Net Wall Area | Rolls (no repeat) |
|---|---|---|
| 10×12 ft, 8 ft | ~315 sq ft | 7 rolls |
| 12×12 ft, 8 ft | ~339 sq ft | 7 rolls |
| 14×16 ft, 9 ft | ~492 sq ft | 10 rolls |
| 12×18 ft, 8 ft | ~420 sq ft | 9 rolls |
Enter room dimensions, openings, roll size, and pattern repeat for an accurate roll count. Compare with the paint calculator if deciding between painting and papering. Vinyl-coated papers wipe clean in kitchens and baths, while grasscloth and silk textures demand careful paste application and are best left to experienced hangers.
Examples
| Example | Result |
|---|---|
| 12×12 ft, 8 ft, 1 door, 2 windows, standard roll | ~7 rolls |
| 10×14 ft, 8 ft, 1 door, 1 window | ~6 rolls |
| 14×16 ft, 9 ft, 2 doors, 2 windows | ~10 rolls |
| 12×12 ft with 24 in pattern repeat | ~9 rolls |
| 16×20 ft, 10 ft, 2 doors, 3 windows | ~13 rolls |
| 8×10 ft accent wall, 8 ft | ~2 rolls |
| 12×18 ft dining room, 9 ft ceilings | ~10 rolls |
Frequently asked questions
A standard single roll (20.5 in × 33 ft) covers about 56 sq ft. Double rolls cover roughly 112 sq ft. Pattern repeats reduce usable area.
Pattern repeat is the vertical distance before the design repeats. Larger repeats mean more waste per strip aligning patterns, increasing rolls needed.
Yes — buy at least one extra roll for mistakes and future repairs. Dye lots change between batches, so matching later is difficult without spare rolls.