1. What is a Wallpaper Calculator?

Definition: This calculator estimates the number of wallpaper rolls needed based on total wall area, roll coverage, and a waste factor.

Purpose: It helps homeowners and decorators determine how many wallpaper rolls to purchase for a project.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( R \) — Rolls needed (whole number)
• \( A \) — Total wall area (square feet)
• \( Roll\_A \) — Area covered by one roll (square feet)
• \( Waste \) — Waste factor (typically 0.1–0.2)

Explanation: The total area is divided by roll coverage (rounded up), then increased by the waste percentage to account for pattern matching and errors.

3. Importance of Accurate Calculation

Details: Proper calculation ensures you purchase enough wallpaper (including extra for mistakes) while avoiding excessive over-purchasing.

4. Using the Calculator

Tips: Enter the total wall area in ft², roll coverage (default 30 ft²), and waste factor (default 0.15). All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: Why do we need a waste factor?
A: The waste factor accounts for pattern matching, trimming, and potential installation errors.

Q2: What's a typical roll coverage?
A: Most standard wallpaper rolls cover about 30 square feet, but check manufacturer specifications.

Q3: When would I increase the waste factor?
A: Use a higher factor (0.2-0.3) for complex patterns, large repeats, or inexperienced installers.

Q4: How do I find the total wall area?
A: Measure wall height and width, then calculate: (Height × Width) - (window/door areas).

Q5: Should I buy extra rolls?
A: Yes, consider buying 1 extra roll beyond calculation for future repairs, as dye lots may vary.