Wallpaper Calculator
Calculate how many rolls of wallpaper you need for your room. Enter your room dimensions, number of doors and windows, and roll size to get an accurate estimate with waste included.
Single vs. Double Rolls
Wallpaper in the US is priced by the single roll but typically sold in double rolls (also called bolts). Understanding the difference is essential for ordering the correct amount:
- Single roll: Approximately 36 square feet of wallpaper, regardless of width. Standard dimensions are 20.5" wide x 33' long or 27" wide x 27' long.
- Double roll: Approximately 72 square feet. This is twice the length of a single roll on one continuous bolt. Most retailers sell double rolls.
- European rolls: Typically 21" wide x 33' long (about 57 sq ft), which is between US single and double rolls.
Always confirm roll dimensions before ordering, as sizes can vary by manufacturer.
Pattern Repeat and Matching
If your wallpaper has a pattern, you'll need extra material to align the design across strips:
- Random match: No pattern alignment needed. Least waste.
- Straight match: The pattern aligns at the same point on each strip. Add the pattern repeat length to each strip height.
- Drop match (half-drop): Every other strip is offset by half the repeat. This creates more waste; add 1.5x the repeat length per strip.
This calculator includes a 15% waste factor to account for pattern matching, trimming, and mistakes. For large pattern repeats (over 12 inches), consider adding an extra roll.
Wallpaper Hanging Tips
- Prepare your walls: Fill holes, sand rough spots, and apply primer or wallpaper sizing for the best adhesion.
- Start at a focal point: Begin hanging next to a door or in the least conspicuous corner, working outward.
- Use a plumb line: Ensure your first strip is perfectly vertical. Walls are rarely perfectly straight.
- Order from the same dye lot: Colors can vary slightly between production runs. Order all your wallpaper at once from the same batch.
- Keep extras: Save at least one extra roll for future repairs or touch-ups.
Accent Wall Calculation
If you're only wallpapering one accent wall, measure just that wall's width and the ceiling height. Use the same formula but only for that single wall rather than the full room perimeter. Most accent walls need 2-3 single rolls depending on the wall size and pattern.