Wallpaper Calculator

Find out exactly how many rolls of wallpaper you need for any room. This calculator accounts for roll size, pattern repeat, doors, and windows to give you an accurate material estimate with minimal waste.

Room Dimensions

Room Perimeter (feet) or enter L×W below

Wall Height (feet)

— or Room Length (feet)

— Room Width (feet)

Wallpaper Roll Details

Roll Width (inches)

Roll Length (feet)

Pattern Repeat (inches) (0 = no pattern)

Deductions — Doors & Windows (sq ft)

Full Breakdown

Room Perimeter

Gross Wall Area

Deductions

Net Wall Area

Usable Area per Roll

Rolls Needed

Single Rolls to Buy

How to Use This Calculator

Enter the room perimeter in feet (or enter length and width to auto-calculate).
Set the wall height (typically 8 ft).
Enter your wallpaper roll width and length (standard US: 20.5″ × 33 ft).
If your wallpaper has a pattern, enter the pattern repeat in inches.
Enter deductions for doors (≈21 sq ft each) and windows (≈12 sq ft each).
Click "Calculate Rolls" for your estimate.

The Formula

Net Wall Area = (Perimeter × Height) − Deductions
Usable Drop Length = Wall Height + Pattern Repeat waste
Drops per Roll = ⌊Roll Length ÷ Drop Length⌋
Usable Area/Roll = Drops per Roll × Roll Width × Drop Length
Rolls = ⌈Net Wall Area ÷ Usable Area per Roll⌉

Standard US single rolls are 20.5″ wide × 33 ft long (≈56 sq ft). Euro rolls are typically 21″ × 33 ft. Pattern repeat adds waste — larger repeats require more rolls.