Walls & Ceilings

Wallpaper Calculator: Estimate Rolls by Room Size

Estimate roll count by calculating the number of wall drops and the usable drops from each roll.

Project measurements

Change the defaults to match your project and the product you plan to buy.

Room length

Room width

Wall height

Roll width

Roll length

Pattern repeat

Price per roll (optional)

Project result

Your wallpaper roll plan

Plan full-height drops, pattern-adjusted cut length, drops per roll and whole-roll quantity.

Open Project Planner →

Planning estimate only. Verify product coverage, package size, supplier specifications and project requirements before purchasing.

Methodology

Formula & assumptions

Required drops

room perimeter ÷ roll width, rounded up

Each vertical strip spans one roll width.

Cut length

wall height rounded up to the next pattern repeat

With no pattern repeat, cut length equals wall height.

Drops per roll

roll length ÷ cut length, rounded down

Only complete wall-height drops count.

Rolls

required drops ÷ drops per roll, rounded up

The result assumes the listed roll dimensions are usable product dimensions.

How to measure this project

Measure the total wall perimeter and the finished wall height. This simplified room model assumes all walls receive wallpaper. For feature walls, large windows or doors, measure the actual wall sections instead of relying on a full-room perimeter.

Before you buy materials

Pattern matching can significantly increase material use because each drop may need to be cut longer to align the repeat. Wallpaper packaging can also use single-roll and double-roll terminology differently, so enter the physical width and total length printed on the product you will buy.

Reference

Pattern repeat effect

Pattern repeat	Cut-length effect	Planning implication
0 in	No repeat adjustment	Most efficient use of roll length.
Small repeat	Minor round-up per drop	May reduce drops per roll near a threshold.
Large repeat	Larger round-up per drop	Can materially increase roll count.
Drop match / special pattern	Product-specific	Follow manufacturer matching instructions.

Questions

Frequently asked questions

Does the wallpaper calculator subtract windows and doors?

Not automatically. For rooms with large openings, calculate only the wall widths that will actually receive wallpaper for a tighter estimate.

What does pattern repeat change?

It can force each wall drop to be cut longer than the wall height so neighboring pieces align. That may reduce the number of complete drops available from each roll.

What if the roll is shorter than one wall drop?

The calculator flags that condition because a standard full-height drop cannot be cut from the entered roll length.

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