Wallpaper Calculator

How to use the wallpaper calculator

1. Choose one wall or a whole room. For a room, enter the floor’s length and width; the calculator papers all four walls.
2. Enter the wall height, and count the doors and windows on the walls you are papering.
3. Read the roll off the label: its width and length, or tap US double roll, European roll or peel and stick.
4. Enter the pattern repeat and match, also on the label (a straight match, a half-drop, or random with no repeat).
5. Read the rolls to buy, including one spare, with the number of strips and the length to cut each one.

The rules the calculator uses

How to measure for wallpaper

Measure the width of each wall and the height from the floor to the ceiling (or to the top of the trim you paper up to). Leave doors and windows in the width: they are handled separately. For a room, the width to cover is the perimeter, twice the length plus twice the width.

Why strips, not square feet

Wallpaper goes up in full-height strips, and a roll can only be cut into whole strips; what is left at the end of a roll is too short for another. That is why two walls with the same area can need a different number of rolls, and why a square-foot calculation usually comes out short.

Cut length and pattern repeat

Each strip is the wall height plus 4 inches for trimming, 2 at the top and 2 at the bottom. With a pattern, the strip is rounded up to a whole number of repeats, so each strip starts at the same point of the pattern and the next one matches it. A half-drop match starts every other strip half a repeat lower, which uses about half a repeat more paper per strip. A random match, or a plain paper, needs no rounding.

Doors, windows and the spare roll

Doors (about 3 × 6⅔ ft) and windows (about 3 × 4 ft) save paper, but the calculator only counts whole strips saved: the short pieces above and below them come from the ends of other strips. Always buy one spare roll at the same time: rolls are printed in batches, and a roll from a later batch can be a slightly different shade.

Standard roll sizes

A US double roll is 20½ inches wide and 33 feet long, about 56 sq ft. A European roll is 0.53 m wide and 10.05 m long, about 57 sq ft. Peel and stick rolls vary; 20½ inches by 18 feet (about 30 sq ft) is common. Wide commercial papers can be 27 or 36 inches: read the label and enter it.

How many rolls of wallpaper for a room: chart

8 ft walls, one door, two windows, US double rolls, 21″ straight-match repeat:

How much wallpaper for an accent wall

8 ft high, no doors or windows; US double rolls with a 21″ repeat, peel and stick at 20½″ × 18 ft with no repeat. Rolls include the spare.

What the pattern repeat does

Cut length and strips per US double roll (33 ft), straight match:

A large repeat on a tall wall can drop a roll from three strips to two, which is 50% more rolls for the same wall.

Three worked examples

A 12 ft accent wall. At 8 ft high with a 21″ straight repeat, each strip is cut to 105″ (100″ rounded up to five repeats). 144″ of wall ÷ 20½″ paper = 8 strips, and a 33 ft roll gives 3 strips, so 3 double rolls cover it: buy 4 with the spare. With a half-drop match the strips are 115½″, still 3 to a roll.

A 12 × 12 ft bedroom. The four walls are 48 ft around: 29 strips across, less 2 strips that one door and two windows save, is 27 strips. At 3 strips a roll that is 9 double rolls, 10 with the spare.

A 14 × 16 ft living room in European paper. With 9 ft walls, a 64 cm (25.2″) repeat, two doors and three windows, each strip is cut to 126″ and a 10.05 m roll gives 3. 35 strips across, less 4 saved by the openings, is 31 strips: 11 rolls, 12 with the spare.

Common wallpaper mistakes

• Calculating by square feet. A roll covers its square footage only if every strip uses it exactly. Whole strips and the repeat always leave offcuts.
• Ignoring the pattern repeat. A large repeat on a tall wall can mean a third more rolls. Read it off the label before you order.
• Buying rolls from two batches. The batch (or lot) number is on the label; rolls from different batches can differ in shade. Buy everything plus a spare at once.
• Measuring only the longest wall. Measure every wall you will paper; corners each take a little extra as the paper wraps.
• Forgetting the trim allowance. Strips cut exactly to the wall height leave gaps at the ceiling and skirting. Allow 2″ at each end.

Read next

• Peel and stick wallpaper accent walls
• White wallpaper ideas to brighten any room
• Burgundy wallpaper designs
• Vintage winter wallpaper ideas
• Accent walls in the living room

Wallpaper questions

How much wallpaper do I need?

Divide the width of the walls by the roll width to get the number of strips. Cut each strip to the wall height plus 4 inches, rounded up to whole pattern repeats, and divide the roll length by that to get strips per roll. Strips ÷ strips per roll, rounded up, plus one spare, is what to buy.

How many rolls of wallpaper do I need for a 12×12 room?

With 8-foot walls, one door, two windows and a 21-inch repeat, about 27 strips of 20½-inch paper, which is 9 US double rolls, or 10 with a spare. A plain paper or a small repeat can save a roll; a large repeat or taller walls can add two or three.

How do you measure for wallpaper?

Measure the width of every wall you will paper and the height from the floor to the ceiling. Do not subtract doors and windows from the width; count them instead. Then read the roll width, roll length, pattern repeat and match from the wallpaper’s label.

How many square feet does a roll of wallpaper cover?

A US double roll (20½ inches × 33 feet) is about 56 sq ft and a European roll (0.53 × 10.05 m) about 57 sq ft, but you will not use all of it: whole strips and the pattern repeat leave offcuts. In practice a double roll papers roughly 40 to 50 sq ft of wall.

What is a wallpaper pattern repeat?

The distance down the paper before the pattern starts again, printed on the label. Every strip must start at the same point of the pattern so the strips match, so each one is cut to a whole number of repeats. The bigger the repeat, the more paper is left over.

What is the difference between a straight and a half-drop match?

In a straight match the pattern lines up straight across from strip to strip. In a half-drop match every second strip is moved down by half a repeat, so the design runs diagonally. A half-drop uses about half a repeat more paper per strip.

How much peel and stick wallpaper do I need for an accent wall?

Count strips the same way: the wall width divided by the roll width. A 10-foot wall takes 6 strips of 20½-inch paper; at 8 feet high a common 18-foot roll gives 2 strips, so 3 rolls, or 4 with a spare. Check your roll’s length, as peel and stick sizes vary by brand.