Free Wallpaper Calculator
Estimate wallpaper rolls for a room, accounting for pattern repeat and openings. Free, fast, and works entirely in your browser with no sign-up required.
Updated
Wallpaper quantity
Add up the length of every wall.
A US double roll is about 56 ft²; a single about 28.
A larger repeat wastes more at every drop.
Rolls needed
6
rolls
- Wall area to cover
- 301ft²
- Usable coverage per roll
- 56.0ft²
How this is calculated
usable coverage = roll coverage × height ÷ (height + repeat); rolls = wall area ÷ usable coverage
- A US double roll covers roughly 56 ft², a single roll about 28 — check the label, European rolls differ again.
- A pattern repeat is wasted at the top of every drop, which is why a large repeat can add several rolls.
- A standard door is treated as 21 ft² and a window as 15 ft².
- Buy every roll from the same batch: dye lots vary visibly between runs.
Frequently Asked Questions
How does the Wallpaper Calculator work?
It applies the formula usable coverage = roll coverage × height ÷ (height + repeat); rolls = wall area ÷ usable coverage. Enter your measurements and the result updates instantly in your browser — nothing is uploaded and no sign-up is needed.
Why should I include a waste allowance?
Offcuts, spillage, breakage and an uneven sub-base all consume material that the raw geometry does not account for. The default allowance is deliberately modest; increase it for complex layouts, and remember that running short usually costs more in a second delivery than the surplus did.
Are the results exact?
They are a close estimate, not a guarantee. A US double roll covers roughly 56 ft², a single roll about 28 — check the label, European rolls differ again. Real materials vary by supplier, moisture content and compaction, so confirm the rate with your supplier before placing a large order.
Is this tool free?
Yes, completely free with no registration. All calculations happen client-side in your browser.
Does it work on mobile?
Yes. The calculator is fully responsive and works on phones and tablets in any modern browser — useful when you are measuring on site.
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About the Wallpaper Calculator
The Wallpaper Calculator works out the wall area to cover, reduces the usable coverage of each roll by the pattern repeat, and converts that into rolls. Enter your measurements and the result updates as you type — there is nothing to submit and nothing to wait for.
Everything runs in your browser. Nothing you enter is sent to a server, there is no sign-up, and there is no usage limit.
Who it's for
Anyone papering a room, especially with a large-repeat pattern.
How the calculation works
usable coverage = roll coverage × height ÷ (height + repeat); rolls = wall area ÷ usable coverage
The result depends on a few standard constants, which are stated on the page rather than hidden:
- A US double roll covers roughly 56 ft², a single roll about 28 — check the label, European rolls differ again.
- A pattern repeat is wasted at the top of every drop, which is why a large repeat can add several rolls.
- A standard door is treated as 21 ft² and a window as 15 ft².
- Buy every roll from the same batch: dye lots vary visibly between runs.
Getting an accurate estimate
Measure twice. Small errors in a linear dimension compound, because material volume scales with two or three of them at once — a 6-inch error across a 20-foot run is over a cubic foot of material on a 4-inch pour.
Keep the waste allowance. The default is deliberately conservative: offcuts, spillage, uneven sub-base and breakage are all real, and running short mid-job usually costs more in a second delivery than the surplus did.
Round up when you order. Suppliers sell in fixed increments — quarter yards, whole bags, full boxes — so treat the figure here as the minimum you need rather than the exact amount to buy.