Wallpaper Calculator
Estimate wallpaper rolls from wall dimensions and roll coverage.
Project details
Enter your measurements below.
Wallpaper is ordered by drops, not just by square footage
Wallpaper can look like an area problem, but roll planning is usually controlled by full-height drops and pattern matching. Two rolls with the same printed square footage may produce different usable coverage when the pattern repeat is large or the ceiling is tall. Use this calculator with the actual roll dimensions and repeat for the paper you selected. Measure wall widths and height carefully, then let the drop length account for trimming and matching. Small openings do not always translate into a full drop saved, so avoid deducting every outlet, door or window as though wallpaper were liquid paint.
Wall height determines the length of each full drop.
A larger repeat can increase the cut length needed to start each strip on the correct motif.
Use the actual roll width and length; 'single' and 'double' roll naming can be confusing across markets.
How to use the Wallpaper Calculator
- Measure the total width of walls that will receive the same wallpaper and record the wall height.
- Enter the wallpaper roll width and roll length exactly as sold, along with the pattern repeat when the design requires matching.
- Use the adjusted drop length to determine how many full drops can be cut from a roll, then calculate how many drops the wall width needs.
- Round to whole rolls and consider keeping matching dye-lot material for repairs or additional sections when appropriate.
Why nominal roll area can mislead
A roll may contain enough total square footage on paper but still fail to produce the required number of full-height matched drops. Drop planning is the safer basis for patterned wallpaper.
Turn the count into a purchase plan
Use whole-roll quantity, then verify the manufacturer's pattern-match instructions and roll lot information before ordering.
Worked example: a patterned paper in an 8 ft room
- Wall width to cover
- 36 ft
- Paper width
- 20.5 in
- Wall height
- 8 ft
- Pattern repeat
- 20.5 in
The repeat can force each strip to be cut longer than 8 ft so the pattern aligns. The calculator therefore plans by usable full-height strips from each roll rather than dividing wall square footage by the roll's printed area.
Practical planning tips
Measure several points if an older room has an uneven ceiling or base line; use a practical maximum drop length rather than the shortest measurement.
Keep doors and windows on the sketch, but remember that strips beside and above an opening still create pattern-matching offcuts.
Order all rolls for a visible room together when possible so matching batch/dye-lot issues are easier to manage.
For half walls or separate accent walls, calculate them as separate runs. Their shorter drops may use rolls more efficiently than a full-height wall.
Common mistakes to avoid
Dividing total wall area by roll area and ignoring pattern repeat.
Assuming the marketing term 'double roll' means the same physical roll size for every brand or country.
Subtracting a window's full area even though wallpaper strips must still be cut around it and matched.
Rounding wall height down or forgetting trimming allowance at the top and bottom of each drop.
Wallpaper Calculator FAQs
Why does pattern repeat increase wallpaper quantity?+
The next strip may need to start farther down the roll so its motif aligns with the previous strip. That matching waste reduces the number of usable full-height drops from a roll.
Should I subtract doors and windows?+
Large openings can reduce material, but simple area deduction can overstate the saving. Strips around and above openings still need pattern matching, so a drop-based plan is more reliable.
What roll dimensions should I enter?+
Use the physical width and length printed for the exact product. Do not rely only on labels such as single roll, double roll or European roll.
Can I calculate an accent wall separately?+
Yes. A separate wall run is often easier to plan because its width, height and pattern use can be considered independently.