Wallpaper Calculator
Wallpaper Roll & Cost Estimator
Enter the total width of all walls to be papered in meters.
Enter the height from floor to ceiling in meters.
Enter the width of any doors to be excluded. Enter 0 if none.
Enter the height of any doors to be excluded. Enter 0 if none.
Enter the width of any windows to be excluded. Enter 0 if none.
Enter the height of any windows to be excluded. Enter 0 if none.
Standard roll width is usually 0.53 meters (53 cm).
Standard roll length is usually 10.05 meters.
Enter the pattern repeat in meters (e.g., 0.64m). Enter 0 if no repeat or free match.
Enter the price of one roll of wallpaper.
Your Wallpaper Estimate
—
Calculations based on wall area, subtracting openings, roll coverage, and accounting for pattern repeat.
Wall Area
— m²
Openings Area
— m²
Net Wall Area
— m²
Rolls Required
—
Wallpaper Cost Breakdown
Visual representation of the total wallpaper cost versus wastage cost.
Roll Usage Details
| Description | Value |
|---|---|
| Roll Width | — m |
| Roll Length | — m |
| Total Roll Area | — m² |
| Pattern Repeat | — m |
| Number of Strips per Roll | — |
| Usable Length per Strip (incl. repeat) | — m |
| Effective Area Covered Per Roll | — m² |
| Total Rolls Required | — |
| Total Cost of Wallpaper | — £ |
| Estimated Wastage Cost | — £ |
Wallpaper Calculator: Estimate Rolls & Cost Accurately
Decorating a room with wallpaper can transform its look and feel, but accurately estimating the amount of wallpaper needed is crucial to avoid costly mistakes. Over-ordering leads to waste, while under-ordering means inconvenient trips back to the store and potential dye lot issues. Our free Wallpaper Calculator simplifies this process, providing precise estimates for the number of rolls and the total cost, ensuring your project runs smoothly from start to finish.
What is the Wallpaper Calculator?
The Wallpaper Calculator is an online tool designed to help homeowners, DIY enthusiasts, and professional decorators determine the exact quantity of wallpaper required for a specific room. It takes into account various room dimensions, the size of wallpaper rolls, and the complexities of pattern matching to provide a reliable estimate.
Who should use it?
Anyone planning to wallpaper a room can benefit from this calculator. This includes:
- Homeowners undertaking DIY decoration projects.
- Professional interior designers and decorators.
- Renovators looking to update a space.
- Individuals who want to accurately budget for wallpapering materials.
Common misconceptions about wallpaper estimation
A common mistake is assuming you just need to measure the square footage of the walls and divide by the square footage of a roll. This approach often fails to account for critical factors like:
- Pattern Repeat: Large or complex patterns require extra paper to ensure the design matches across seams, leading to significant wastage.
- Roll Size Variations: Wallpaper rolls come in different standard sizes, and failing to use the correct dimensions will lead to inaccurate calculations.
- Deductions for Openings: While doors and windows reduce the paperable area, simply subtracting their area isn't always sufficient due to the need for careful cutting around them.
- Wastage: Even with simple patterns, some wastage is unavoidable during cutting and application.
Our Wallpaper Calculator addresses these complexities to provide a more realistic and accurate wallpaper estimate.
Wallpaper Calculator Formula and Mathematical Explanation
The calculation involves several steps to accurately determine the number of wallpaper rolls and their cost. Here's a breakdown of the formulas used:
1. Calculate Total Wall Area:
Total Wall Area = Room Perimeter × Room Height
Where Room Perimeter = 2 × (Room Width + Room Depth) – *Note: For simplicity in this calculator, we use a single 'Room Width' representing the total linear footage of walls to be papered.* If your room is rectangular with distinct width and depth, you'd calculate the perimeter as 2*(Width + Depth). For this calculator, assume `Room Width` is the total perimeter in meters.
Corrected for calculator input: Total Wall Area = Room Width × Room Height
2. Calculate Area of Openings (Doors & Windows):
Total Opening Area = (Door Width × Door Height) + (Window Width × Window Height)
3. Calculate Net Wall Area:
Net Wall Area = Total Wall Area – Total Opening Area
4. Calculate Area Coverage Per Roll:
This is the most complex part, accounting for pattern repeat.
Effective Roll Width = Wallpaper Roll Width
Number of Strips per Roll = Floor(Room Height / Usable Length Per Strip)
Where Usable Length Per Strip = Room Height + Pattern Repeat (if pattern match is needed), otherwise just Room Height. For simplification, we calculate how many full strips fit, assuming pattern repeat is added to each strip length calculation if specified.
A more practical approach for "strips per roll":
Number of Strips per Roll = Floor(Wallpaper Roll Length / (Room Height + Pattern Repeat))
Effective Area Covered Per Roll = Number of Strips per Roll × Wallpaper Roll Width × (Room Height)
Let's refine: The total length of wallpaper needed is `Net Wall Area / Wallpaper Roll Width`. The number of full-length strips of height `Room Height + Pattern Repeat` you can get from one roll is `Floor(Wallpaper Roll Length / (Room Height + Pattern Repeat))`. So, the total linear meters needed is `Net Wall Area / Wallpaper Roll Width`. The number of rolls is then `Ceiling(Total Linear Meters Needed / Linear Meters per Roll)`.
A simpler, widely accepted method: Calculate the total area to be covered. Calculate the usable area from one roll, considering pattern repeat. Divide total area by usable roll area.
Simplified Calculation Logic Used:
Area Per Roll = Wallpaper Roll Length × Wallpaper Roll Width
Number of Rolls = Ceiling(Net Wall Area / Area Per Roll)
Adjustment for Pattern Repeat: If pattern repeat is significant, the number of strips obtainable from a roll is reduced. A common rule of thumb is to add the pattern repeat to the required drop length. The number of drops from a roll is `Floor(Roll Length / (Room Height + Pattern Repeat))`. The total wallpaper needed is `(Net Wall Area / Wallpaper Roll Width)`. Therefore, `Total Rolls = Ceiling(Total Wallpaper Needed / (Drops Per Roll * Roll Width))`. A more direct way: Calculate the number of strips needed: `Ceiling(Net Wall Area / Wallpaper Roll Width) / Number of Strips Per Roll`. A practical adjustment is often adding 10-20% for wastage and pattern matching.
Calculator's Practical Logic:
1. Calculate `Net Wall Area`. 2. Calculate `Total Linear Meters Required` = `Net Wall Area` / `Wallpaper Roll Width`. 3. Calculate `Strips Per Roll` = `Floor(Wallpaper Roll Length / (Room Height + Pattern Repeat))`. If `Pattern Repeat` is 0, `Strips Per Roll` = `Floor(Wallpaper Roll Length / Room Height)`. 4. Calculate `Total Rolls Needed` = `Ceiling(Total Linear Meters Required / (Strips Per Roll * Wallpaper Roll Width))`. 5. Add a buffer for wastage and difficult cuts. A common buffer is 10-15%. For this calculator, we'll use a base calculation and mention the buffer.
Revised Practical Logic for Calculator:
1. Total Wall Area = Room Width * Room Height
2. Opening Area = (Door Width * Door Height) + (Window Width * Window Height)
3. Net Wall Area = Total Wall Area - Opening Area
4. Area Per Roll = Wallpaper Roll Length * Wallpaper Roll Width
5. Rolls Based On Area = Ceiling(Net Wall Area / Area Per Roll)
6. Strips Obtainable Per Roll = Floor(Wallpaper Roll Length / (Room Height + Pattern Repeat)) (if Pattern Repeat > 0, else Floor(Roll Length / Room Height))
7. Total Strips Needed = Ceiling(Net Wall Area / Wallpaper Roll Width)
8. Rolls Based On Strips = Ceiling(Total Strips Needed / Strips Obtainable Per Roll)
9. Final Rolls Required = Ceiling(MAX(Rolls Based On Area, Rolls Based On Strips) * 1.10) (Applying 10% buffer)
5. Calculate Total Cost:
Total Cost = Final Rolls Required × Wallpaper Cost Per Roll
6. Calculate Wastage Cost:
Total Area of Rolls Purchased = Final Rolls Required × (Wallpaper Roll Length × Wallpaper Roll Width)
Wastage Area = Total Area of Rolls Purchased – Net Wall Area
Wastage Cost = Wastage Area × (Wallpaper Cost Per Roll / Area Per Roll)
Variables Table
| Variable Name | Meaning | Unit | Typical Range |
|---|---|---|---|
| Room Width | Total linear width of walls to be papered. | meters (m) | 1.0 – 50.0+ |
| Room Height | Floor to ceiling height. | meters (m) | 2.0 – 5.0 |
| Door Width | Width of doors to be excluded. | meters (m) | 0.0 – 1.5 |
| Door Height | Height of doors to be excluded. | meters (m) | 0.0 – 2.5 |
| Window Width | Width of windows to be excluded. | meters (m) | 0.0 – 3.0 |
| Window Height | Height of windows to be excluded. | meters (m) | 0.0 – 2.5 |
| Wallpaper Roll Width | Standard width of a wallpaper roll. | meters (m) | 0.45 – 0.76 (commonly 0.53) |
| Wallpaper Roll Length | Standard length of a wallpaper roll. | meters (m) | 5.0 – 15.0 (commonly 10.05) |
| Pattern Repeat | Vertical distance before the pattern repeats. | meters (m) | 0.0 – 1.0+ (0.0 for no repeat/free match) |
| Wallpaper Cost Per Roll | Price of a single roll of wallpaper. | Currency (£, $, €) | 10.00 – 100.00+ |
Practical Examples (Real-World Use Cases)
Example 1: Standard Bedroom
Inputs:
- Room Width: 12 m
- Room Height: 2.5 m
- Door Width: 0.8 m
- Door Height: 2.0 m
- Window Width: 1.5 m
- Window Height: 1.2 m
- Wallpaper Roll Width: 0.53 m
- Wallpaper Roll Length: 10.05 m
- Pattern Repeat: 0.64 m
- Wallpaper Cost Per Roll: £25.00
- Total Rolls Required: 4 rolls
- Total Cost: £100.00
- Estimated Wastage Cost: £10.00
- Net Wall Area: 27.04 m²
- Rolls Based on Area: 3 rolls
- Rolls Based on Strips: 4 rolls
Example 2: Living Room with Minimal Pattern
Inputs:
- Room Width: 18 m
- Room Height: 2.8 m
- Door Width: 0.9 m
- Door Height: 2.1 m
- Window Width: 2.0 m
- Window Height: 1.4 m
- Wallpaper Roll Width: 0.53 m
- Wallpaper Roll Length: 10.05 m
- Pattern Repeat: 0.0 m (Free Match)
- Wallpaper Cost Per Roll: £35.00
- Total Rolls Required: 5 rolls
- Total Cost: £175.00
- Estimated Wastage Cost: £17.50
- Net Wall Area: 46.86 m²
- Rolls Based on Area: 5 rolls
- Rolls Based on Strips: 5 rolls
How to Use This Wallpaper Calculator
Using the Wallpaper Calculator is straightforward. Follow these steps for accurate results:
- Measure Your Room: Accurately measure the total width of all walls you intend to wallpaper (this is the 'Room Width' input). Measure the height from the floor to the ceiling ('Room Height').
- Measure Openings: Measure the width and height of any doors and windows you want to exclude from the wallpaper area. If there are none, enter '0' for these fields.
- Know Your Wallpaper Specs: Find the width and length of your chosen wallpaper roll (usually stated on the packaging or product description). Note the pattern repeat height in meters – this is crucial for wallpapers with designs. If it's a plain or 'free match' paper, enter '0'.
- Enter Roll Cost: Input the price you are paying for a single roll of wallpaper.
- Click Calculate: Press the "Calculate" button.
How to interpret results
- Total Rolls Required: This is the primary result – the minimum number of rolls you should purchase. Always round up if your calculation results in a fraction. Our calculator applies a small buffer (10%).
- Total Cost: The total amount you can expect to spend on the wallpaper itself.
- Estimated Wastage Cost: An approximation of the cost attributed to paper used for pattern matching, offcuts, and minor errors.
- Intermediate Values: These provide insight into the calculation:
- Wall Area: The gross surface area of the walls.
- Openings Area: The total area of doors and windows.
- Net Wall Area: The actual area that needs to be covered by wallpaper.
- Rolls Needed (Intermediate): Shows calculations based purely on area vs. based on fitting strips, highlighting how pattern repeat impacts quantity.
- Chart & Table: These offer a visual and detailed breakdown of cost allocation and roll specifications.
Decision-making guidance
The results from this wallpaper calculator should guide your purchasing decisions:
- Order Quantity: Always buy the number of rolls recommended, or even one extra if you're inexperienced or the wallpaper is expensive and hard to re-order.
- Budgeting: Use the 'Total Cost' to set your budget accurately. Remember to factor in costs for adhesive, tools, and potential professional help if needed.
- Pattern Match Strategy: If your pattern repeat is high, be prepared for potentially more wastage and ensure you order enough rolls from the start.
Key Factors That Affect Wallpaper Calculation Results
Several elements influence the accuracy of wallpaper estimations and the final cost:
- Pattern Repeat: This is arguably the most significant factor. High pattern repeats (e.g., over 0.6m) require much more paper as you often discard portions of the roll to align the design. Free match or zero repeat papers are the most economical.
- Room Dimensions: Larger rooms naturally require more wallpaper. However, the ratio of height to width also matters, affecting how many 'drops' (vertical strips) can be cut from a single roll. Complex room shapes with many corners or alcoves can also increase wastage.
- Wallpaper Roll Size: Standard European rolls (like 0.53m x 10.05m) are common, but US rolls or specialty papers can vary significantly. Using the correct roll dimensions in the calculator is vital.
- Number and Size of Openings: While deductions are made for doors and windows, fitting the wallpaper around these can sometimes require more precise cuts and lead to small wastage pieces, especially around intricate frames or bay windows.
- Wallpaper Application Skill: An experienced decorator might be more efficient with cuts and pattern matching, potentially leading to less wastage than a DIY novice. However, it's always safer to calculate based on needing a bit extra.
- Wallpaper Type and Material: Some materials are more forgiving or easier to handle than others. Heavy vinyls might be more prone to tearing, while textured papers can sometimes hide minor imperfections in the wall or application. This calculator focuses on quantity, not material properties.
- Buying Strategy: Purchasing rolls from the same batch or dye lot is critical for consistent colour. If you are short, re-ordering might result in a colour variation, making it necessary to re-paper entire walls or even the room. This emphasizes ordering enough initially.
Frequently Asked Questions (FAQ)
Q1: How much extra wallpaper should I buy?
Our calculator includes a 10% buffer for wastage and pattern matching. For complex patterns or if you're a beginner, consider adding an extra 5-10% (i.e., round up your final calculated roll number). It's always better to have a little left over than to run short.
Q2: What is 'pattern repeat' and why does it matter?
Pattern repeat is the vertical distance on the wallpaper where the design begins to repeat. For wallpapers with a pattern, you must align the design across each strip. This means you often cannot use the full length of the roll for every strip, leading to extra paper being needed. A 'free match' or '0m repeat' requires no such alignment.
Q3: Can I use the calculator for ceilings?
This calculator is designed for vertical walls. Wallpapering a ceiling requires a different approach, often needing more careful handling and potentially more wastage due to gravity and working overhead. For ceilings, calculate the area and add a larger percentage (e.g., 15-20%) for safety.
Q4: What if my room isn't rectangular?
For rooms with non-standard shapes (L-shaped, alcoves, etc.), the best approach is to measure each section of wall accurately, sum their widths to get the total 'Room Width' input, and carefully measure any openings within those sections. Complex features might increase wastage beyond the calculator's estimate.
Q5: Does the calculator account for wastage around corners?
The calculator primarily accounts for wastage due to pattern repeat and standard offcuts. Significant wastage around complex internal/external corners or features is harder to predict precisely and is partially covered by the general buffer. Careful cutting is key in these areas.
Q6: What's the difference between a 'straight match' and a 'random match'?
A 'straight match' (or 'half drop match') means the pattern on the next strip needs to align with the corresponding point halfway down the previous strip. A 'random match' (or 'free match') means the pattern doesn't need to align across seams, making application simpler and reducing waste. Our calculator handles '0.0' pattern repeat as a random/free match.
Q7: Should I buy rolls from the same batch number?
Absolutely. Wallpaper rolls are often dyed in batches, and slight colour variations can occur between batches. Always check the batch number on the rolls and ensure all rolls used on a single wall (or ideally, the entire room) are from the same batch to maintain colour consistency.
Q8: How does wallpaper cost affect the total project budget?
The cost of wallpaper itself can vary dramatically, from budget-friendly options to luxury designer papers. This calculator focuses solely on the quantity and direct cost of the wallpaper rolls. Remember to budget separately for primer, adhesive, tools (knives, paste brushes, rollers, smoothing tools), and potentially professional labour if you're not DIYing.
Related Tools and Internal Resources
- Paint Calculator – Estimate the amount of paint needed for walls and ceilings.
- Tile Calculator – Calculate the number of tiles required for floors and walls.
- Guide to Choosing Wallpaper Patterns – Tips on selecting the right wallpaper for your space.
- DIY Wallpaper Hanging Guide – Step-by-step instructions for a professional finish.
- Room Dimension Calculator – Quickly calculate room area and perimeter.
- Linear Foot Calculator – Useful for various measurement needs in home improvement.