# Wallpaper Roll Calculator

Drops and rolls from perimeter, height and pattern repeat.

- Page: https://jianzhujisuan.com/en/wallpaper
- Category: Finishes (https://jianzhujisuan.com/en/c/finishes)
- Chinese version: https://jianzhujisuan.com/zh/wallpaper.md
- Data checked: 2026-10-25

## Quick result

With the default inputs (Room perimeter 18 m, Wall height 2.8 m, Roll length 10 m, Roll width 0.53 m, Pattern repeat 0.32 m repeat, Openings area 0 m²): **Rolls needed 12 rolls**

## Inputs

| Parameter | Type | Default | Unit | Note |
|---|---|---|---|---|
| Room perimeter | number | 18 | m | (length + width) × 2 |
| Wall height | number | 2.8 | m |  |
| Roll length | number | 10 | m |  |
| Roll width | number | 0.53 | m |  |
| Pattern repeat | select | 0.32 m repeat | — |  |
| Openings area | number | 0 | m² |  |

## Formula

- **Cut length**: L = wall height + pattern repeat (0.1 m trim if plain)
- **Drops per roll**: n = floor(roll length ÷ L)
- **Drops needed**: N = ceil(perimeter ÷ roll width)
- **Rolls**: R = ceil(N ÷ n)

## Worked example

An 18 m perimeter at 2.8 m with 0.53 × 10 m rolls and no repeat: 2.90 m per drop, 3 drops per roll, 34 drops, so 12 rolls. At a 0.64 m repeat each drop is 3.44 m, only 2 fit per roll, and 17 rolls are needed.

## Questions

### Why does a pattern repeat cost so much extra?

With a repeat every drop must start at the same point in the pattern: a 2.8 m wall plus a 0.64 m repeat is 3.44 m, so a 10 m roll yields two drops and leaves 3.12 m unusable. That is why large repeats waste so much. Calculate with this formula rather than dividing area, or you will run short.

### Can I deduct doors and windows?

Rarely, because paper is hung in full drops: the strips above and below an opening are cut from a full drop and the offcut seldom matches elsewhere. You only save when a door runs full height or a window sits exactly between two drops. This tool shows net area but does not reduce the roll count.

### How much adhesive?

About 1 kg of powder, once mixed, covers 20-25 m², or 0.3-0.4 kg per 5.3 m² roll. Primer is separate at roughly 8-10 m² per kg. Prime the wall first: adhesive soaked straight into the filler coat will fail in sheets later.

## Related tools

- [Paint Coverage Calculator](https://jianzhujisuan.com/en/paint-coverage): Enter room size, ceiling height, openings and number of coats to get total area, litres needed and how many cans to buy.
- [Tile Calculator](https://jianzhujisuan.com/en/tile-count): Enter the area to cover, pick a tile size and waste factor to get tiles and boxes required.
- [Flooring Quantity Calculator](https://jianzhujisuan.com/en/flooring): Planks and packs from room size and board format, with waste by laying pattern.
- [Ceiling Grid Calculator](https://jianzhujisuan.com/en/ceiling-grid): Main and cross runner lengths, hangers and fittings from ceiling size.
- [Plasterboard Quantity Calculator](https://jianzhujisuan.com/en/gypsum-board): Sheets, screws and joint tape from area, sheet size and layers.
- [Skirting Board Calculator](https://jianzhujisuan.com/en/skirting): Metres and lengths from perimeter and doorways, with waste.

---

Generated by BuildCalc. All calculations run in your browser; no data is uploaded. Formulas follow national standards and common trade practice; local codes govern.