Wallpaper Calculator

How to Calculate How Many Wallpaper Rolls You Need

Wallpaper adds texture and personality to any room — though if you prefer a simpler finish, our paint calculator can estimate paint for the same walls. Getting the right number of rolls avoids costly shortages where dye lots might not match.

The Wallpaper Calculation Formula

Rolls needed = (Room Perimeter × Room Height) ÷ Usable Area per Roll

The usable area per roll depends on the pattern repeat:

• No pattern repeat: Full roll length is usable
• With pattern repeat: Each strip loses material to pattern alignment

Step-by-Step Guide

1. Measure room perimeter — Add all wall lengths together (or 2 × (length + width)).
2. Measure room height — Floor to ceiling, typically 2.5m.
3. Check wallpaper specs — Roll width, length, and pattern repeat (on the label).
4. Enter the values — Our calculator handles the math including waste.

Understanding Pattern Repeat

What You'll Need

• Wallpaper rolls — As calculated, plus 1 extra roll for safety
• Wallpaper paste — Pre-mixed or powder (1 pack per 5 rolls typical)
• Smoothing brush or squeegee — For removing air bubbles
• Sharp utility knife — For clean cuts
• Plumb line or level — For perfectly vertical hanging
• Seam roller — For pressing joints flat

Tips for Success

• Order all rolls from the same batch — Batch numbers ensure consistent color
• Start from the window wall — Work away from natural light to hide seams
• Prepare your walls — Fill cracks, sand, and apply sizing/primer. If the walls need replastering, use our drywall calculator to estimate materials
• Allow for doors and windows — Include partial strips above and below openings

When to Hire a Professional

Consider a professional wallpaper hanger for pattern-heavy designs, feature walls with large repeats, textured wallpapers (grasscloth, fabric-backed), or stairwells and high ceilings. If you are renovating the entire room, our flooring calculator can help you estimate laminate or vinyl for the floor at the same time.