Construction

Wallpaper Calculator

Estimate rolls of wallpaper for a room, with waste for matching.

Wall area

Coverage per roll

Waste (%)

Price per roll ($)

Calculated Output

Rolls needed (rolls) 17

Total cost ($) 0

Formula: rolls = wall area × (1 + waste) ÷ coverage per roll

Step-by-Step Breakdown

1. Values used:

2. Wall area = 400

3. Coverage per roll = 28

4. Waste = 15 %

5. Price per roll = 0 $

7. Rolls needed = 17rolls

8. Total cost = 0$

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The math behind it

Rolls = wall area × (1 + waste) ÷ usable coverage per roll, rounded up.

A standard US double roll covers ~56 ft² (single ~28 ft²); patterned papers need more waste.

400 ft² of wall, 28 ft²/roll, 15% waste → 400 × 1.15 ÷ 28 = 17 rolls.

Why so much waste?

Pattern repeats must align between strips, so the top of each strip is often cut off and discarded.