Walls & Trim guide
How to estimate wallpaper rolls
Count drops, not square feet. Wallpaper is hung in full-height strips (drops), and whatever is left at the end of a roll is often too short for another one. Dividing wall area by roll area can leave you a roll short.
1. Count the drops
A 12 ft (144 in) wall with 20.5 in wide paper needs 144 ÷ 20.5 = 7.02, so 8 drops. Rounding up matters: the last drop is partly trimmed but you still need a full length.
2. Find the cut length of each drop
With 8 ft walls and 4 in of total trim, each drop is 100 in. If the paper has a 21 in repeat, each drop must start at the same point in the pattern, so the cut rounds up to 5 × 21 = 105 in.
3. Drops per roll, then rolls
Rolls = round up(drops ÷ drops per roll)
A 33 ft (396 in) roll gives 396 ÷ 100 = 3.96, so 3 full drops. Eight drops ÷ 3 = 2.67, so 3 rolls, with one spare drop.
Why roll area misleads
The same roll is 20.5 in × 33 ft = 56.4 sq ft. A 96 sq ft wall divided by 56.4 suggests 1.7 rolls, so 2. The drop method says 3, because each roll ends with 96 in of paper, just short of a fourth 100 in drop, and that offcut cannot hang as a full-height strip.
Before you order
- Read the roll width, length, and repeat from the label; they vary by brand.
- Check whether the price is per single roll while packaging is double rolls.
- Order from one batch number, and consider a spare roll for repairs.
- Half-drop and mural designs need the maker’s own planning instructions.