Wallpaper Calculator
The Wallpaper Calculator estimates the total number of wallpaper rolls required to cover your walls. This calculator helps homeowners and DIYers plan wallpaper projects by accounting for wall dimensions, roll size, and extra material for waste. Whether you are wallpapering a single accent wall or an entire room, this tool provides a reliable estimate for your material needs.
This calculator provides estimates only. Actual wallpaper needs may vary based on pattern repeat, wall irregularities, doors, windows, and installation method. Consult a professional painter or wallpaper installer for complex projects.
Use this free online Wallpaper Calculator to calculate your total wallpaper rolls required. Simply enter your wall dimensions, roll size, and waste factor to instantly get results in rolls and square feet. This estimate helps you purchase the right amount of wallpaper for your project.
How Total Wallpaper Required Is Calculated
The calculator finds the total surface area of all walls by multiplying wall height, wall width, and the number of walls. It then calculates how much area one roll of wallpaper can cover by converting the roll width from inches to feet and multiplying by roll length. A waste factor is added to account for pattern matching and trimming. Finally, the adjusted wall area is divided by the coverage per roll to find how many rolls you need.
Rolls = (Wall Height × Wall Width × Number of Walls × (1 + Waste%)) ÷ (Roll Length × Roll Width ÷ 12)
Where:
- Wall Height = vertical height of wall in feet
- Wall Width = horizontal width of wall in feet
- Number of Walls = total walls to cover
- Waste% = waste factor expressed as decimal (10% = 0.10)
- Roll Length = length of wallpaper roll in feet
- Roll Width = width of wallpaper roll in inches (divided by 12 to convert to feet)
The result is always rounded up because you cannot purchase partial rolls. This formula works best for rectangular walls and does not account for large openings like doors and windows.
What Your Wallpaper Calculator Result Means
The number of rolls tells you how many packages of wallpaper to buy for your project. This estimate includes extra material for waste but does not subtract areas for doors, windows, or other openings. For rooms with large windows or doors, you may need fewer rolls than calculated. For rooms with complex patterns that require matching, you may need more.
| Project Size | Typical Wall Area | Estimated Rolls |
|---|---|---|
| Small bathroom | 100-200 sq ft | 2-4 rolls |
| Standard bedroom | 350-450 sq ft | 5-8 rolls |
| Large living room | 500-700 sq ft | 8-12 rolls |
| Full room (10x12 ft) | 380-400 sq ft | 6-8 rolls |
Always check the roll specifications on the wallpaper package before purchasing. Different brands may have different roll lengths and widths, which changes coverage. When in doubt, purchase one extra roll to ensure you have enough material from the same dye lot.
Accuracy, Limitations & Common Mistakes of the Wallpaper Calculator
How Accurate Is the Wallpaper Calculator?
This calculator provides a reasonable estimate for standard rectangular walls. The accuracy depends on correct measurements and understanding that actual coverage varies based on pattern repeat and installer skill. For simple projects with plain or small-pattern wallpaper, the estimate is typically within one roll of actual needs. Professional installers often have more precise methods for complex patterns.
Limitations of the Wallpaper Calculator
The calculator does not account for pattern repeat, which can add 10-20% more material for large patterns. It assumes flat rectangular walls and does not subtract for doors, windows, or built-in furniture. It also does not account for sloped ceilings, alcoves, or irregular wall shapes. Very tall walls over 10 feet may require special ordering. Always consult product specifications and consider professional advice for valuable or expensive wallpaper.
Common Mistakes to Avoid
- Forgetting to measure all walls separately when they have different widths, which leads to incorrect total area.
- Not accounting for pattern repeat on large prints, which requires more material to match seams correctly.
- Purchasing wallpaper from different dye lots, which can cause visible color differences between strips.
- Measuring in inches but entering values as feet, resulting in dramatically incorrect calculations.
Frequently Asked Questions
Who is this Wallpaper Calculator for?
This calculator is designed for homeowners, renters, and DIY enthusiasts planning interior wallpaper projects. It works well for standard rooms with rectangular walls. Professional contractors may use more detailed methods for complex installations.
How often should I use this calculator?
Use this calculator whenever you plan a new wallpaper project or want to compare different wallpaper options. It is helpful during the planning phase to estimate material costs and budget before making purchases.
Does this calculator work for all wallpaper types?
Yes, the calculator works for most standard wallpaper rolls including prepasted, unpasted, and peel-and-stick varieties. However, grasscloth, fabric, and specialty wallcoverings may have different coverage rates and installation requirements.
Can I use this calculator if I have vaulted ceilings or irregular walls?
The calculator provides a starting estimate for irregular spaces. For vaulted ceilings, use the average wall height. For irregular shapes, break the walls into rectangular sections and calculate each separately. Consider consulting a professional for complex installations.
Is the Wallpaper Calculator free to use?
Yes, this calculator is completely free with no sign-up required. It works on any device including phones, tablets, and computers.
References
- National Guild of Professional Paperhangers — Wallpaper Estimation Guidelines
- This Old House — How to Calculate Wallpaper Needed
- Home Improvement Research Institute — Wallcovering Material Standards
Calculation logic verified using publicly available standards.
View our Accuracy & Reliability Framework →