Wallpaper Calculator: Determine Exactly How Many Rolls You Need
Planning to refresh your room with new wallpaper? Our Wallpaper Calculator is the precise tool you need. It eliminates the guesswork by calculating the exact number of rolls required, factoring in crucial details like pattern matching and the area of doors and windows to prevent costly shortages or waste.
How to Use the Wallpaper Calculator
To get your personalized estimate, simply provide the following information. Accuracy here ensures the best result.
| 1. Room Measurements | Input the room's length, width, and height. For non-standard rooms, you can directly enter the total wall surface area. |
| 2. Doors & Windows | Specify the number and size of all doors and windows. Use standard sizes or enter custom dimensions for a precise calculation. |
| 3. Wallpaper Roll Details | Enter the roll's cost, its length and width, and the pattern repeat—a critical measurement found on the packaging for matching designs. |
After entering your data, the calculator provides:
- Adjusted Wall Height: The length per strip, adjusted for pattern alignment.
- Net Wall Area: Total area to cover, minus openings and plus pattern waste.
- Rolls Required: The total number of rolls to buy, always rounded up.
- Project Cost: The total estimated price for all wallpaper.
Understanding the Calculator's Accuracy
While our tool provides a highly accurate estimate, especially regarding pattern repeat, we recommend purchasing an extra 10% of wallpaper. This buffer accounts for complex cuts, trimming errors, or future repairs. For rooms with unusually complex shapes, consulting a professional is advised.
Frequently Asked Questions (FAQ)
How do I manually calculate wallpaper for a room?
Follow these steps for a basic estimate:
- Calculate the total wall area: 2 × (Width + Length) × Height.
- Subtract the total area of all doors and windows.
- Divide this net area by the area a single roll covers (Roll Width × Roll Length).
- Always round the final number up to the nearest whole roll.
What is "pattern repeat" and why is it important?
The pattern repeat is the vertical distance between where a wallpaper's design pattern starts again. A larger repeat means you need longer strips to match the pattern between adjacent rolls, resulting in more material waste. Not accounting for it is a common reason for purchasing insufficient wallpaper.
How do I adjust my calculations for pattern repeat?
You must use an "effective" wall height instead of the actual height. Divide your room's height by the pattern repeat, round this result up, and then multiply by the repeat value. Use this new height in your area calculations.
Effective Height = ceil(Room Height / Pattern Repeat) × Pattern Repeat
How many 1.5m x 6m rolls are needed for a 28 m² room?
Using the formula:
Number of Rolls = Total Area / (Roll Width × Roll Length)
Number of Rolls = 28 m² / (1.5 m × 6 m) = 3.11...
Since you cannot buy partial rolls, you must round up, requiring 4 rolls in total.