What is Wallpaper Calculator?

Wallpaper Calculator estimates how many rolls of wallpaper you need to cover a room. Enter your room dimensions, the roll size, and the pattern repeat length, and get an accurate count that accounts for waste and matching.

Choose whole-room or accent-wall mode, then enter the dimensions, plus the number and size of doors and windows. Tap a preset for standard roll sizes or type your own roll width, length, and pattern repeat. Switch between metres and feet, pick a pattern match type to set the waste allowance (or override it with your own percentage), and add a roll price for a cost estimate. The calculator subtracts openings from the wall area, applies the waste buffer, and rounds up to whole rolls. A small diagram shows your room layout so you can sanity-check before shopping.

How to use

1. Step 1 — Enter the room's width, length, and height, plus the number and size of doors and windows.
2. Step 2 — Tap a common roll-size preset or enter the roll width, length, and optional pattern repeat. Pick a match type to pre-fill the waste allowance (or set your own), and add a price per roll for the total material cost.
3. Step 3 — View the rolls needed alongside the minimum count, the waste buffer applied, and the estimated cost if you entered a roll price.

When to use

• Estimating a wallpaper order before a refresh of a single room or feature wall.
• Comparing prices across rolls with different lengths or widths to find the cheapest option for the same coverage.
• Adding contingency rolls when the wallpaper has a large vertical pattern repeat.

Result

Your room is 4 m × 5 m with 2.5 m ceilings, one door (0.9 × 2.1 m), and two windows (1.2 × 1.5 m each). With standard 0.53 × 10 m rolls, the calculator says you need 10 rolls.

FAQ

Why does pattern repeat add so many rolls?

To line up the design across adjacent strips, you cut each strip to the next repeat boundary, not to the wall height. A 64 cm repeat on a 250 cm wall means up to 64 cm of waste per drop, which adds up fast across a room.

Should I round up the result manually?

The calculator rounds up to whole rolls and adds a waste allowance. Picking a match type pre-fills a sensible default — 10% for a free match, 15% for a straight match, 20% for a drop match — but you can type your own percentage in the Waste Allowance field. For tricky patterns or first-time hanging, bumping it to 20-25% or ordering one spare roll is a common safety net that costs less than a second batch later.

Does it handle slanted ceilings or stairwells?

Not directly. Break the wall into rectangular sections, calculate each one separately, and sum the rolls. Stairwells need careful planning around the diagonal cuts — a paperhanger usually adds 15-20% extra to those rooms.

What's the difference between standard and grasscloth or specialty rolls?

Specialty rolls like grasscloth often come in non-standard widths (76 cm vs 53 cm) and longer lengths. Enter the actual roll dimensions printed on the spec sheet rather than using the standard defaults to avoid coming up short.

Do I need to subtract small windows and doors?

It depends on the pattern. For plain or small-repeat designs, subtracting openings saves rolls. For large patterned designs, paperhangers often keep the full wall area in the estimate because the offcuts above and below windows rarely line up for reuse.

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