Wallpaper Calculator

How to measure

1. Measure the total perimeter of all walls to be papered.
2. Measure wall ceiling height accurately, excluding baseboards and crown mouldings.
3. Check wallpaper roll length, roll width, and pattern repeat distance printed on packaging.
4. Determine pattern waste (5% for plain/random match; 15–20% for large vertical repeats).

Input guide

• Enter total wall perimeter length and wall height in meters or feet.
• Input standard roll width in centimeters (e.g., 53 cm) or inches (e.g., 21 or 27 in).
• Input standard roll length in meters (e.g., 10 m) or feet (e.g., 33 ft).
• Enter price per roll to calculate total wallpaper budget.

Formula

The calculator determines total vertical strips required around the room perimeter.

It calculates whole usable strips obtainable from one roll based on wall height.

It applies pattern matching waste and rounds upward to whole rolls.

Worked example: Accent feature wall with patterned wallpaper

1. A wall run measuring 12.0 m perimeter with a 2.7 m ceiling height.
2. Using standard European rolls (53 cm / 0.53 m width × 10.0 m length).
3. Required strips = 12.0 m ÷ 0.53 m = 23 strips.
4. Strips per roll = Floor(10.0 m ÷ 2.7 m) = 3 strips per roll.
5. Rolls required = (23 ÷ 3) × 1.10 waste = 8.43 rolls, rounded up to 9 rolls.

At 40 USD per roll, estimated wallpaper material cost is 360 USD for 9 rolls.

Buying advice

• Order all rolls in a single transaction with identical batch / dye lot numbers.
• Keep one unopened roll in storage for future seam repairs or water damage patches.
• Apply an acrylic wall sizing primer to facilitate future dry stripping without tearing drywall.

Common mistakes

• Subtracting normal windows and running short on pattern-matched strips.
• Forgetting to allow 10 cm (4 inches) top and bottom trimming allowance per strip.
• Hanging strips without checking vertical plumb lines with a laser or level.
• Mixing rolls with different dye lot serial numbers.