One of the most common questions we get is:
“Do I need to subtract the area of windows and doors when working out how many rolls of wallpaper I need?”
✅ Short Answer
No — when we help calculate roll quantities, we don’t deduct doors or windows.
It's too tricky to estimate accurately without seeing the space, and it often doesn’t reduce how many drops you'll need.
🔍 Why We Don’t Subtract
Even if you're not wallpapering over a door or window, you usually still need full drops of wallpaper to maintain the pattern across the wall. Here's why:
- Doors and windows often interrupt — but don’t eliminate — full wallpaper drops
- Pattern repeats, drop layout, and trimming all affect how much paper you’ll use
- Trying to subtract by hand is one of the most common causes of under-ordering
This is especially true for bold or offset-pattern wallpapers like many of the designs we sell.
📐 When It Might Save a Drop
If you’ve got a very large window or multiple doorways, you might be able to reuse leftover pieces (above or below openings) and get an extra drop out of a roll.
But whether that works depends on:
- The wallpaper’s pattern repeat
- The height of your walls
- The exact layout during installation
In those cases, we recommend asking your wallpaper hanger to do the calculation. They’ll know if they can make use of offcuts or adjust the layout to save material.
💡 Our Rule of Thumb
Measure the full wall as if the windows and doors aren’t there.
This gives you a safe estimate and avoids the risk of coming up short.
🛠 Need Help?
We’re happy to help calculate how many rolls you’ll need — just send us your wall dimensions and the wallpaper you’re looking at.
Just note that we don’t subtract windows or doors from our estimates — but we do allow for pattern repeats and trimming waste.