Single rolls and double rolls
Across the US, wallpaper is quoted per single roll and delivered as double rolls, also called bolts: twice the paper on one core. York describes its Rifle Paper Co. designs as 27 in wide and 13.5 ft long per single and ships them as 27 in × 27 ft doubles. Brewster bolts measure 20.5 in by 33 ft. Peel-and-stick is its own thing: Tempaper sells singles of 20.5 in by 16.5 ft.
Set up in feet, the wallpaper calculator above begins on the 20.5 × 33 bolt with an unpatterned paper, in a 12 by 14 ft room. Answers are counted in doubles; double them again for the singles that price lists use.
Why the roll’s length matters as much as its width
Bolts only give complete lengths. Eight-foot walls plus 4 in of trim make each length 100 in for a plain paper; 396 in of bolt gives three and leaves 96 in, just shy of a fourth. Line up a 20.5 in straight repeat and each length grows to 102.5 in, still three. A 27 ft double with a 27 in drop match gives two. The chart underneath runs common rooms in both, and the working beside the calculator’s answer does the same for yours.
US roll sizes
| Roll | Area on the roll | As the maker states it |
|---|---|---|
| US double roll, 20.5 in × 33 ft | 56.4 sq ft | "Wallpaper is packaged in bolts. 1 Bolt = 56 FT2 {20.5-in X 33-ft}" (Brewster) |
| US double roll, 27 in × 27 ft | 60.7 sq ft | Sold as a "Double Roll (27in x 27.0ft)" (York) |
| Tempaper peel and stick, 20.5 in × 16.5 ft | 28.2 sq ft | "20.5 in. x 16.5 ft. = 28.18 sq. ft." (Tempaper) |
Double rolls for common rooms
8 ft walls, one door, one window, 4 in trim a drop. Single rolls are twice the double rolls, for comparing prices quoted per single roll.
| Room | 20.5 in × 33 ft, 20.5 in straight | 27 in × 27 ft, 27 in drop match |
|---|---|---|
| 10 × 10 ft | 8 double (16 single) | 9 double (18 single) |
| 10 × 12 ft | 9 double (18 single) | 10 double (20 single) |
| 12 × 12 ft | 10 double (20 single) | 11 double (22 single) |
| 12 × 14 ft | 11 double (22 single) | 12 double (24 single) |
| 14 × 16 ft | 12 double (24 single) | 14 double (28 single) |