What is a pattern repeat?

It is the vertical distance before a wallpaper pattern repeats itself. To match the design between drops, each strip except the first wastes up to one repeat. Enter 0 for a plain or randomly matchable paper.

What size is a standard roll?

A standard European roll is 0.53 m wide and 10 m long (5.3 m²). US rolls vary — often 0.52 m × 7.3 m. Check your paper’s label and enter its actual width and length for an accurate count.

Should I subtract doors and windows?

Yes, for a tighter estimate. The calculator lets you enter the total area of openings to subtract. Many installers still buy one extra roll for matching and repairs, so consider rounding up.

What if my wallpaper has no pattern to match?

Set the pattern repeat to 0. The strip length becomes just the wall height, more drops fit per roll, and you need fewer rolls. Plain or randomly matchable papers still need a small allowance for trimming top and bottom, but nothing like a full repeat.

Should I buy an extra roll even if the maths says I have enough?

Often yes. Keeping one spare roll from the same batch covers mistakes, future damage repairs, and the shade-matching problem of buying later. Many installers recommend one extra roll regardless of the calculated count, especially for patterned papers.

Cooking & DIY/Home Calculators

Wallpaper Roll Calculator

Wallpaper is sold by the roll, and patterned papers waste length matching the design from drop to drop. Buy too few and you stop mid-wall with a dye-lot mismatch; buy too many and the shop may not take returns. This calculator works out the number of drops, the usable length per roll after pattern matching, and the rolls to buy.

Enter the wall’s total length and height, the roll width and length (a standard European roll is 0.53 m × 10 m), and the pattern repeat if the paper has one. The calculator allows for openings by letting you subtract doors and windows, and rounds up to whole rolls so the whole wall comes from one batch.

It is the calculation that gets wallpapering right in one trip — the number of rolls allowing for pattern matching and openings, rounded up so the whole wall comes from one dye-lot and the joins disappear.

Total wall length (m)

Wall height (m)

Roll width (m)

Roll length (m)

Pattern repeat (m)

Openings area to deduct (m²)

Enter your values to see the result.

How this is calculated

The gross wall area is the total wall length × height. The openings area you enter (doors and windows) is subtracted to give a net area, though many installers still buy one extra roll for matching. The number of vertical strips needed is the total wall length ÷ roll width, rounded up. The length required per strip is the wall height plus one pattern repeat (if any), because each strip after the first must be cut to align the pattern, wasting up to one repeat per drop.

The number of drops per roll is the roll length ÷ strip length, floored to a whole drop — a 10 m roll cut into 2.5 m strips with a 0.32 m repeat gives strips of 2.72 m, and floor(10 ÷ 2.72) = 3 drops per roll. The rolls to buy is the strips needed ÷ drops per roll, rounded up to a whole roll. Rounding up ensures the whole wall is papered from one batch, which matters because wallpaper is printed in dye-lots that can shade-match poorly across batches.

The model assumes a standard rectangular wall and a consistent pattern repeat. For walls with many openings, subtracting the openings area tightens the estimate but the strip-based calculation already ignores the openings when counting strips, so the result is conservative. Very large pattern repeats, murals or half-drop matches waste more than the model assumes; for those, add an extra roll. Always check the roll’s actual width and length on the label — US rolls are often shorter than the European 10 m standard.

Worked example

A 10 m × 2.4 m wall, 0.53 m × 10 m rolls, 0.32 m pattern repeat, 3 m² of openings.

1Gross area = 10 × 2.4 = 24 m²; net = 24 − 3 = 21 m².
2Strips needed = ceil(10 ÷ 0.53) = 19 strips.
3Strip length = 2.4 + 0.32 = 2.72 m.
4Drops per roll = floor(10 ÷ 2.72) = 3.
5Rolls = ceil(19 ÷ 3) = 7 rolls.

Frequently asked questions

What is a pattern repeat?: It is the vertical distance before a wallpaper pattern repeats itself. To match the design between drops, each strip except the first wastes up to one repeat. Enter 0 for a plain or randomly matchable paper.
What size is a standard roll?: A standard European roll is 0.53 m wide and 10 m long (5.3 m²). US rolls vary — often 0.52 m × 7.3 m. Check your paper’s label and enter its actual width and length for an accurate count.
Should I subtract doors and windows?: Yes, for a tighter estimate. The calculator lets you enter the total area of openings to subtract. Many installers still buy one extra roll for matching and repairs, so consider rounding up.
What if my wallpaper has no pattern to match?: Set the pattern repeat to 0. The strip length becomes just the wall height, more drops fit per roll, and you need fewer rolls. Plain or randomly matchable papers still need a small allowance for trimming top and bottom, but nothing like a full repeat.
Should I buy an extra roll even if the maths says I have enough?: Often yes. Keeping one spare roll from the same batch covers mistakes, future damage repairs, and the shade-matching problem of buying later. Many installers recommend one extra roll regardless of the calculated count, especially for patterned papers.

Related calculators

Method: strips = ceil(wall length ÷ roll width); drops per roll = floor(roll length ÷ (height + repeat)); rolls = ceil(strips ÷ drops per roll). Standard European roll 0.53 m × 10 m. Last updated: September 2026.

These results are general estimates from established formulas and conversion factors. Paint coverage, tile yields, concrete volumes, fuel economy, oven behaviour and clothing and shoe sizes vary by product, surface, vehicle, oven and brand. Always confirm with your supplier, the product label or the brand’s own size chart before buying or acting on a calculation.