Understanding Your Wallpaper Estimate

Calculating the correct number of wallpaper rolls can be tricky, especially with pattern repeats. This calculator helps you estimate the quantity by considering your wall dimensions, roll size, pattern details, and an additional waste factor.

How to Use the Calculator

1. Wall Dimensions:
   • Enter the Total Length of All Walls you plan to wallpaper.
   • Enter the Wall Height (from floor to ceiling).
   • Select the unit (meters or feet) for these dimensions.
2. Openings (Optional): Enter the number of standard-sized doors and windows. The calculator can deduct their area. However, for wallpapering, it's often recommended *not* to deduct for smaller openings, or to only deduct for very large ones, as you'll cut around them and may need the full strip for pattern matching. Consider this based on your project.
3. Wallpaper Roll Details:
   • Enter the Roll Width and Roll Length as specified on the wallpaper label. Select the appropriate units.
   • Enter the Vertical Pattern Repeat Length. If your wallpaper is plain or has a "random match," enter 0. This is crucial for patterned papers.
4. Additional Waste Factor: Enter a percentage for additional waste (e.g., 10%). This covers mistakes, trimming around awkward areas, and having a little extra for future repairs. This is on top of waste inherently generated by pattern matching.
5. Click "Estimate Wallpaper Rolls."

Interpreting Your Results

• Wall Areas: Shows gross wall area, deducted area for openings, and the net area to be covered.
• Roll & Strip Details: Displays your input roll dimensions, the calculated cut length needed for each strip (accounting for pattern repeat), how many such strips you can get from one roll, and the total number of strips your walls require.
• Initial Rolls Needed: The number of rolls calculated purely from strip requirements before adding the extra waste factor.
• Total Rolls Recommended: The final estimated number of rolls, including the additional waste factor, rounded up to the nearest whole roll. This is generally the number you should consider purchasing.

Understanding Pattern Repeat

Pattern repeat is the vertical distance between where the pattern starts over again. When hanging patterned wallpaper, each strip must be cut longer than the wall height to allow you to align the pattern with the adjacent strip.

• No Repeat / Random Match: The simplest. You can use almost the entire roll length efficiently. Enter 0 for pattern repeat.
• Straight Match: The pattern matches straight across strips. The calculator assumes this type if a pattern repeat > 0 is entered. Each strip needs to be cut to a length that is a multiple of the pattern repeat and covers the wall height.
• Drop Match (Half-Drop, Quarter-Drop): More complex. Every other strip is offset by a portion of the pattern repeat. This typically results in more waste. This calculator uses a simplified approach for straight matches; for drop matches, you might need to add a higher waste percentage or consult a professional calculator.

Our calculator determines the `Cut Length per Strip` by finding the smallest multiple of the `Pattern Repeat Length` that is greater than or equal to the `Wall Height`. This ensures each strip can be pattern matched.

General Tips for Wallpapering

• Buy All Rolls at Once: Ensure all rolls are from the same batch number (dye lot) to avoid slight color variations.
• Surface Preparation: Walls should be clean, smooth, dry, and properly primed. Old wallpaper should be removed.
• "Book" Your Wallpaper: After applying paste (if not pre-pasted), gently fold the wallpaper pasted-side-to-pasted-side for a few minutes to allow the paste to activate and the paper to relax. Follow manufacturer's instructions.
• Start in a Corner: Or near a focal point, and work your way around the room. Use a plumb line for your first strip to ensure it's perfectly vertical.