How to Measure a Wall for Wallpaper: The Complete Panel Guide
To measure a wall for Think Noir wallpaper, measure the wall width at its widest point and divide by the panel width for your chosen material: 19 inches for Peel and Stick Wallpaper, 25 inches for Traditional Wallpaper. Round that number up to the nearest whole number to get your panel count. Then measure the wall height at its tallest point and choose the panel height option that fully covers it. That is the complete calculation for most walls.
Think Noir panels are installed side by side without overlapping, so the panel width is the only variable that changes between materials. The process for slanted walls, walls with doors, and walls with windows is the same as a rectangular wall. Always measure at the tallest and widest points, regardless of obstacles or angles.
- Peel and Stick panels are 19" wide. Traditional panels are 25" wide. These are the two numbers you will divide the wall width by.
- Always measure at the tallest point for height and the widest point for width, including on slanted walls and walls with obstacles.
- Always round your panel count up to the next whole number. Never round down.
- For walls with doors or windows, do not subtract the obstacle from your measurement. Order panels for the full wall and cut around the opening during installation. This preserves the pattern match.
- Peel and Stick panels are available in 48", 96", 108", and 120" heights. Traditional panels come in 96", 108", and 120".
- When in doubt, order one extra panel. Re-ordering later risks a batch mismatch. One spare panel costs far less than that risk.
What Panel Sizes Does Think Noir Wallpaper Come In?
Before measuring, know exactly what you are ordering. Think Noir panels are not sold as rolls. They are individual panels installed edge to edge across the wall.
| Material | Panel Width | Available Heights | Best For |
|---|---|---|---|
| Peel and Stick Wallpaper | 19 inches | 48", 96", 108", 120" | Renters, accent walls, temporary applications, anyone who wants to redecorate without commitment |
| Traditional Wallpaper | 25 inches | 96", 108", 120" | Long-term installations, high-traffic rooms, bathrooms, anywhere durability matters more than removability |
The 48" height option is exclusive to Peel and Stick and works well for half-wall applications, above wainscoting, or below a chair rail. For all full-height walls, use the 96", 108", or 120" options, selecting whichever one fully clears your ceiling height.
What Tools Do You Need to Measure a Wall for Wallpaper?
- Metal tape measure. Not a fabric or plastic one. Metal holds straight across longer distances and gives an accurate reading at the ceiling line where a soft tape will sag.
- Pencil and notepad. Write every measurement down immediately. Do not rely on memory, especially if you are measuring more than one wall.
- Calculator. The arithmetic is simple, but doing it in your head risks a rounding error that costs you a panel.
Measure in inches throughout. Think Noir panel widths and heights are all stated in inches, and dividing in the same unit avoids any conversion mistakes.
How Do You Measure a Rectangular Wall?
A rectangular wall is the straightforward case. Every panel is the same height, every seam runs floor to ceiling, and the pattern repeats predictably across the full width.
The floral bedroom above shows exactly this: a clean, full-height accent wall with panels running edge to edge and the pattern aligned continuously across the whole surface. This is the interior design by Melissa, using the Blush Watercolor Floral Peony Wallpaper.
- Measure the wall width from edge to edge at its widest point. Write it down.
- Measure the wall height from floor to ceiling at the tallest point. Write it down.
- Divide the width by 19 (Peel and Stick) or 25 (Traditional). Round up to the next whole number. That is your panel count.
- Choose the panel height option that equals or exceeds your wall height measurement.
Worked example: Wall is 120" wide and 102" tall.
| Material | Calculation | Raw Result | Panels to Order | Panel Height to Order |
|---|---|---|---|---|
| Peel and Stick (19" wide) | 120 ÷ 19 | 6.3 | 7 panels | 108" |
| Traditional (25" wide) | 120 ÷ 25 | 4.8 | 5 panels | 108" |
The wall is 102" tall, so the 96" height option falls short. The next option up is 108", which clears it with 6 inches to spare for trimming at the ceiling and floor.
How Do You Measure a Slanted Wall?
Slanted walls, like staircase walls or walls under a pitched roof, look more complicated than they are. The measuring method is identical to a rectangular wall. Measure at the tallest point for height and at the widest point for width. Every panel is cut to match the angle during installation.
The entryway staircase above is a strong example: the botanical pattern runs continuously from panel to panel, which is only possible when every panel is ordered at the full height and the matching is planned before installation. This is the interior design by Lauren, using the Green Vintage Botanical Foliage Wallpaper.
- Measure the wall height at the tallest point of the slope.
- Measure the wall width at its widest point.
- Divide width by 19 (Peel and Stick) or 25 (Traditional). Round up.
- Choose the panel height option that covers the tallest point of the wall.
The most common mistake on slanted walls is choosing the panel height based on the shorter end of the slope. Do not do this. Every panel needs to reach the tallest point of the wall so that the pattern aligns when panels are trimmed to the angle.
Worked example: Slanted staircase wall is 120" wide at the widest point and 102" at the tallest point of the slope.
| Material | Calculation | Raw Result | Panels to Order | Panel Height to Order |
|---|---|---|---|---|
| Peel and Stick (19" wide) | 120 ÷ 19 | 6.3 | 7 panels | 108" |
| Traditional (25" wide) | 120 ÷ 25 | 4.8 | 5 panels | 108" |
The result is identical to the rectangular wall example. That is the point: the measuring logic does not change for a slanted wall.
How Do You Measure a Wall with a Door or Window?
Doors, windows, and built-in furniture are measured as if they do not exist. Order panels for the complete wall width and height, then cut around the obstacle during installation. This is the only approach that maintains a consistent pattern match from one side of the opening to the other.
The bedroom above shows the result clearly: the peony pattern runs seamlessly across both doors and the wall sections between them, as if the doors were never there. Subtracting the doors from the panel count would have broken that continuity. This is the interior design by Natalie, using the Vintage Grey Peony Design Wallpaper.
- Measure the full wall width from edge to edge, ignoring any doors or windows.
- Measure the full wall height from floor to ceiling at the tallest point, ignoring any obstacles.
- Divide width by 19 (Peel and Stick) or 25 (Traditional). Round up.
- Choose the panel height option that covers the full wall height.
- Order the full panel count and cut around the obstacle during installation.
Worked example: Wall with two doors is 120" wide and 102" tall.
| Material | Calculation | Raw Result | Panels to Order | Panel Height to Order |
|---|---|---|---|---|
| Peel and Stick (19" wide) | 120 ÷ 19 | 6.3 | 7 panels | 108" |
| Traditional (25" wide) | 120 ÷ 25 | 4.8 | 5 panels | 108" |
If the wall has a very large obstacle, such as patio doors that span most of the wall width, contact Think Noir customer service before ordering. Unusually large openings occasionally change the practical panel count and it is worth a quick check before placing the order.
A Quick Reference: Panel Count Formula
| Wall Width | Peel and Stick Panels (19" wide) | Traditional Panels (25" wide) |
|---|---|---|
| Up to 76" | 4 panels | 4 panels |
| 77" to 95" | 5 panels | 4 panels |
| 96" to 114" | 6 panels | 4 to 5 panels |
| 115" to 133" | 7 panels | 5 panels |
| 134" to 152" | 8 panels | 6 panels |
| 153" to 171" | 9 panels | 7 panels |
| 172" to 190" | 10 panels | 8 panels |
For walls wider than 190", continue dividing by 19 or 25 and rounding up. Always confirm your calculation against your actual measurements rather than relying solely on the table above.
What Are the Most Common Measuring Mistakes to Avoid?
| Mistake | What Goes Wrong | How to Avoid It |
|---|---|---|
| Rounding down the panel count | One panel short, pattern match is broken on the final strip, re-order needed | Always round up. One extra panel is cheap insurance. |
| Choosing the wrong panel height | Panels do not reach the ceiling; the top of the wall is exposed | Always choose the panel height option above your wall measurement, not equal to it. |
| Measuring at the shortest point on a slanted wall | Panels on the tall side of the slope fall short; pattern mismatch | Always measure at the tallest point, full stop. |
| Subtracting obstacles from the panel count | Pattern continuity breaks at the edges of doors and windows | Measure the full wall, order for the full wall, cut during installation. |
| Using a soft or fabric tape measure | Tape sags across long spans, giving a measurement that is 1 to 2 inches short | Use a rigid metal tape measure only. |
| Measuring in centimetres and dividing by inch-based panel widths | Completely wrong panel count | Measure in inches throughout. Panel widths are 19" and 25". |
Frequently Asked Questions
How do I calculate how many wallpaper panels I need?
Measure your wall width in inches at the widest point. Divide by 19 for Peel and Stick Wallpaper or by 25 for Traditional Wallpaper. Round the result up to the next whole number. Then choose the panel height option that fully covers your wall at its tallest point.
How wide are Think Noir wallpaper panels?
Peel and Stick panels are 19 inches wide, available in 48", 96", 108", and 120" heights. Traditional panels are 25 inches wide, available in 96", 108", and 120" heights. Panels are installed side by side without overlapping.
How do I measure a slanted wall for wallpaper?
Measure at the tallest point for height and the widest point for width, exactly as you would a flat wall. Order panels tall enough to cover the peak of the slope. The excess is trimmed to the angle during installation. Never base your panel height on the shorter end of the slope.
Should I subtract doors and windows from my wallpaper order?
No. Measure the full wall as if the obstacle does not exist and order the full panel count. The wallpaper is cut around the door or window during installation. Subtracting the opening results in broken pattern continuity at the edges of the opening.
What if I am unsure how many panels to order?
Always round up. One extra panel on hand is far less costly than a re-order placed weeks later, which risks a difference in batch or print run. If you have an unusual room shape or a wall configuration you are not sure how to measure, contact Think Noir customer service before placing the order.
Do I measure differently for peel and stick versus traditional wallpaper?
The measuring process is identical. The only difference is the divisor: 19 for Peel and Stick, 25 for Traditional. Because Traditional panels are wider, you will need fewer panels for the same wall. Make sure you are using the right panel width for the material you are actually ordering.
Ready to Order?
Accurate measurements are the difference between a seamless installation and a last-minute re-order. Measure twice, use a metal tape, round up, and choose the panel height that clears your ceiling. Everything else follows from those four steps.
If you have not chosen a design yet, order wallpaper samples first to confirm the pattern, color, and scale in your actual room before committing to a full panel order. And if you have any questions about your measurements or your wall configuration, contact Think Noir customer service before you buy. Getting the count right the first time is always easier than managing a re-order.
Browse the full wallpaper collection and use the sizing information above to place your order with confidence.
