Wallpaper Amount Calculator
Calculate wallpaper rolls from wall dimensions, door deductions, and pattern repeat.
Returns roll count with waste for standard, Euro, and bolt-width rolls.
Wallpaper calculations require knowing your wall area, the roll dimensions, and the pattern repeat distance. Getting this wrong means either running short mid-project or buying too many expensive rolls.
Standard roll sizes:
- US standard single roll: 27 inches wide × 13.5 feet long = 30.4 sq ft (usable: ~25 sq ft after trimming)
- US double roll: 27 inches wide × 27 feet long = 60.75 sq ft (usable: ~50 sq ft)
- European standard: 20.5 inches wide × 33 feet long = 56.4 sq ft (usable: ~46 sq ft)
Pattern repeat types:
- Random/no match — No pattern alignment needed. Least waste (5–10%).
- Straight match — Pattern aligns at the same height on each strip. Moderate waste (10–15%).
- Drop match — Pattern aligns at half the repeat distance. Most waste (15–25%).
The formula:
- Calculate total wall area: Perimeter × Height
- Subtract openings: Doors (21 sq ft each) + Windows (15 sq ft each)
- Divide net area by usable coverage per roll
- Add waste factor for pattern matching
- Round up to next whole roll
Pattern repeat impact: A 24-inch (61 cm) pattern repeat on an 8-foot wall means you lose up to 24 inches per strip in alignment waste. Smaller repeats (under 12 inches) waste less.
Buying tips:
- Always buy from the same dye lot (batch number) to ensure consistent color
- Buy 1–2 extra rolls beyond the calculation for mistakes, repairs, and future patches
- Most stores allow returns of unopened rolls within 30–60 days
- Measure twice, order once — running short mid-project means waiting for new stock
Tip: Wallpaper is sold as single rolls but usually packaged as double rolls. Always confirm with your retailer whether the roll length listed is single or double before calculating.