Wallpaper Roll Calculator

How to estimate your wallpaper rolls

1. Choose metric or feet and inches, then enter each wall width and the shared wall height. Use full dimensions without subtracting doors or windows. For different heights, make separate estimates.
2. Enter the usable width and continuous length of one physical roll from its label. Select free, straight or half-drop match. Check the combined top-and-bottom trim and enter the vertical repeat for a patterned match.
3. Review the full strips per wall, planned strip length and whole-roll estimate. Patterned modes reserve one full repeat at the start of every roll. Add optional spare rolls separately and confirm the product requirements before ordering.

Why strips and pattern allowances matter

Each wall width is divided by the usable roll width and rounded upward to a whole strip. Separate walls are rounded separately. A narrow edge offcut is not assumed to cover another wall, and short roll remnants are not joined to make a full-height strip.

Free match uses the wall height plus your combined trim allowance. Straight match rounds that length upward to a complete vertical repeat. The half-drop estimate uses that same rounded length plus another half repeat for every planned strip.

For straight and half-drop modes, one additional full repeat is reserved from each roll for initial pattern alignment. The remaining length is divided by the planned strip length and rounded downward. This deliberately simple method can allow more material than an optimized cutting plan.

The total strip count is divided by the planned strips per roll and rounded upward. Any spare rolls you choose are then added as separate whole rolls. There is no hidden percentage allowance, and a seller’s single-roll or double-roll name is not substituted for the physical dimensions you enter.

Wallpaper quantity examples

A 6 m wall at 2.3 m height, a 60 cm wide by 10 m long roll and 10 cm total trim require 10 strips. With free match, each planned strip is 240 cm long, four fit a roll, and the estimate is three rolls before spares.

For the same wall and roll with a 70 cm straight repeat, the planned strip length is 280 cm. After reserving 70 cm at the start of each roll, three strips fit, so the estimate is four rolls.

With the same 70 cm repeat in half-drop mode, each planned strip is 315 cm long. Only two fit after the per-roll alignment reserve, so the estimate is five rolls. An installer may obtain a different quantity using another cutting arrangement.

Where this estimate applies

Use one continuous-roll product on vertical walls with a shared height and known usable width. Doors and windows are not deducted. Slopes, murals, precut panels, paired A/B rolls, quarter-drop patterns, reverse hanging, overlap that has not been accounted for, and optimized offcut reuse need a product-specific plan.

Measurements, damaged lengths, seam positions, pattern placement, batch consistency and installation choices can change the quantity. The initial trim value is an editable starting allowance, not a manufacturer instruction. A result saying no planned strip fits refers to these allowances, not proof that the product cannot be used.

Calculations in your browser

The tool calculates from the measurements in your browser without intentionally uploading or saving them. Copy writes the current estimate only when requested. Normal site services and consent settings remain separate.