BCBetter Calculators

Wallpaper Calculator

Calculate how many rolls of wallpaper you need for any room.

🧮

Enter your values and click Calculate

How It Works

Total wall area = 2 × (length + width) × height — the combined area of all four walls. Deductions: each door reduces the area by 21 sq ft (a standard 3×7 ft door); each window by 15 sq ft (an average double-hung window). Coverable area = total wall area − deductions. Rolls needed = ceil(coverable area ÷ roll coverage). One additional roll is added as a buffer for pattern matching waste, trimming errors, and future touch-up repairs. Always buy from the same production run (same batch number) to ensure color and pattern consistency — wallpaper can vary subtly between batches. For rooms with large pattern repeats (12 inches or more), consider adding an additional 10–20% to the coverable area before dividing by roll coverage, as more material is wasted aligning the pattern at each seam.

Examples

Standard Bedroom
12×10 ft room, 8 ft ceiling, 1 door, 2 windows, standard 56 sq ft rolls.
Result: Wall area ≈ 345 sq ft minus 51 sq ft deductions = 294 sq ft. About 7 rolls (6 + 1 buffer).
Accent Wall Only
One 14 ft wall, 8 ft ceiling, no doors or windows, 56 sq ft rolls.
Result: About 120 sq ft of wall area. 3 rolls (2 + 1 buffer).
European Single Rolls
12×12 ft room, 9 ft ceiling, 2 doors, 3 windows, European 29 sq ft rolls.
Result: Wall area ≈ 432 sq ft minus 87 sq ft = 345 sq ft. About 13 rolls (12 + 1 buffer).

Frequently Asked Questions

How much wallpaper does a standard roll cover?
US wallpaper rolls are commonly sold as 'double rolls' containing about 56–57 square feet of material, even though they may be labeled or priced as single rolls. European single rolls typically contain 29 square feet; European double rolls about 57 sq ft. Always read the label — it will state the usable square footage per roll. The calculator lets you enter your specific roll coverage to handle any roll size.
How do I account for pattern repeats?
Patterned wallpaper with a repeat requires extra material to align the pattern at each seam. A small repeat (under 3 inches) adds minimal waste. A large repeat (12–24 inches) can waste 25% or more of each roll. To estimate, measure the pattern repeat length from the label and calculate the additional drop needed per strip. As a rule of thumb, add one full pattern repeat length per strip to your coverage calculation, or simply add 15–20% to the total wall area before dividing by roll coverage.
Can I wallpaper over existing wallpaper?
It is generally not recommended, though it is technically possible in some cases. Papering over existing wallpaper can cause adhesion problems, bubbling, seam visibility, and adds weight that can pull both layers off the wall. If the existing wallpaper is firmly adhered with no peeling, bubbles, or loose seams, some installers will apply new paper over it. However, the standard professional recommendation is to strip the old wallpaper first, prime the walls, and start fresh for the best result.
What tools do I need to hang wallpaper?
Basic wallpaper installation requires: a smoothing brush or plastic smoother, a sharp utility knife or wallpaper scissors, a seam roller, a level and chalk line for the first plumb line, a sponge and bucket for cleaning paste off the surface, and a wallpaper trough or paste table if using non-pasted wallpaper. Pre-pasted wallpaper only requires water to activate the adhesive. Unpasted wallpaper requires a wallpaper adhesive applied with a brush or pasting machine. Starting with a plumb vertical line on the first wall is critical — walls are rarely perfectly square.

Related Calculators

life✨

Paint Calculator

Calculate how many gallons of paint you need to cover a room.

Calculate →
life✨

Flooring Calculator

Calculate how much flooring you need including waste allowance and total cost.

Calculate →