Estimate complete wallpaper rolls, full-height strips, and optional paste packs for one wall, multiple same-height walls, or a room in US customary or Canadian metric units.
The roll estimate accounts for straight pattern repeat, total top-and-bottom trimming, and an additional strip allowance. Opening area reduces paste needs but not full-height strip count.
Enter the total length and consistent height of the wall area.
Enter the total area that does not need wallpaper.
Reduces net area and paste, but not full-height strip count.
Use the dimensions printed on the roll label.
Straight-match repeat and total top-and-bottom trimming allowance.
Extra full strips for mistakes, damage, difficult cuts, and repairs.
Recommended Guidelines
• 10% — Standard wallpaper projects
• 15% — Corners, difficult cuts, or beginner DIY work
• 20% — Complex rooms or additional repair material
Enter the coverage printed on one paste pack or bucket.
Leave blank for peel-and-stick wallpaper or when paste is not required.
Wall Area
—
sq ft
Net Wall Area
—
sq ft
Usable Roll Coverage
—
sq ft / roll
Paste Needed
—
packs
—
Wallpaper Rolls Needed
Additional strip allowance: —
🪣 — Paste Packs
Based on — sq ft per pack
Estimate disclaimer: This estimate is for planning purposes only. Actual costs may vary based on location, material prices, labor rates, taxes, fees, exchange rates, and project conditions.
Calculate the full-width strips required across the wall, then determine how many full-height, pattern-matched strips fit in one roll. Divide the total strips by the usable strips per roll and round up to the next complete roll. Taller walls, larger repeats, and extra trimming can reduce the number of strips per roll.
Wallpaper is not a simple wall-area-divided-by-roll-area purchase. Each drop must span the full wall height, including the trimming allowance, and a straight-match design may make that drop longer. The useful yield is the number of complete matched strips that can be cut from one roll.
The calculator divides the combined length of same-height walls by the roll width and rounds up. A final partial strip position still requires a full-width piece of material.
Total top-and-bottom trimming is added to wall height. For a straight match, that cut is then rounded up to the next complete multiple of the entered pattern repeat.
Roll length is divided by the matched strip length and rounded down. Any remainder that cannot make another full-height matched strip does not increase the yield.
The waste-adjusted strip count is divided by usable strips per roll and rounded up. If the project needs even one more strip than the current rolls supply, another complete roll is required.
Theoretical roll area describes the total sheet of material, but it does not show how many complete drops the roll can produce. Wall height, trimming, pattern alignment, and the leftover length at the end of the roll can all reduce usable yield. Compare the calculator's strips-per-roll result—not nominal area alone—when evaluating products.
Door and window area reduces net wall area and optional paste packs only. It does not reduce strip count because opening positions and reusable offcuts are unknown. The entered waste percentage is applied to base strips, then rounded up to whole extra strips; it does not automatically add a separate spare roll.
Gross Wall Area = Total Wall Length × Consistent Wall Height
Net Wall Area = Gross Wall Area − Entered Opening Area, with a minimum of zero
Cut Length = Wall Height + Total Trimming Allowance
Matched Length = Cut Length rounded up to the next straight pattern repeat
Strips Needed = Wall Length ÷ Roll Width, rounded up
Total Strips = Strips Needed × (1 + Additional Strip % ÷ 100), rounded up
Strips per Roll = Roll Length ÷ Matched Strip Length, rounded down
Rolls Needed = Total Strips ÷ Strips per Roll, rounded up
Paste Packs = Net Wall Area ÷ Label Coverage per Pack, rounded up when paste coverage is entered
These examples call the same calculation function as the interactive result. They show how strip length, pattern repeat, and physical roll size change the purchase quantity.
A 20 ft × 8 ft wall uses 20.5 in × 35 ft rolls, 4 in of trimming, and a 10% strip allowance. With no pattern repeat, the 8.33 ft cut stays the same length. The production result is 12 base strips, 4 strips per roll, and 4 whole rolls after allowance.
Adding a 24 in straight repeat rounds each matched drop to 10 ft. Yield falls from 4 to 3 strips per roll, so the result rises from 4 to 5 whole rolls. Wall area did not change; usable roll yield did.
Keeping the same wall, repeat, trimming, openings, and allowance but using a 27 in × 45 ft roll produces 9 base strips and 4 matched strips per roll. The production result is 3 whole rolls, compared with 5 for the narrower, shorter roll.
Enter wall and roll lengths in feet, roll width, repeat, and trimming in inches, and opening or paste coverage in square feet.
Combine wall lengths only when the walls have the same height. Calculate different-height sections separately.
Roll sizes, single-roll and double-roll packaging, panels, and product coverage vary by manufacturer.
Door and window area reduces paste coverage, but exact strip savings require each opening’s position, width, and height.
Ordering an appropriate spare roll from the same dye lot can help with future repairs and colour consistency.
Wallpaper must be cut into full-height strips. A roll can have enough nominal area yet still be unable to supply another complete strip after wall height, trimming, and pattern matching are considered. This calculator therefore bases the roll count on strip yield rather than area alone.
It divides the combined length of same-height walls by the physical roll width and rounds up. A requirement of 10.2 strip widths becomes 11 full-width strips because a partial strip position still needs material.
Wall height plus the entered top-and-bottom trimming allowance sets the initial cut length. Longer cuts reduce the number of full-height strips that fit along a roll and can increase the number of whole rolls required.
For a straight match, each cut length is rounded up to a whole multiple of the entered repeat. That alignment can consume more length per strip and reduce roll yield. Half-drop, offset, reverse-hang, and other special matches are not modelled.
The entered opening area reduces net wall area and the optional paste estimate. It does not reduce the full-height strip or roll count because the calculator does not know each opening's position or whether an offcut can be reused.
The calculator first finds the number of usable matched strips per roll, then divides the required strips by that yield and rounds up. Wallpaper is purchased as complete rolls, so a remaining strip requirement needs another roll.
It applies the entered percentage to the base strip count and rounds up to an additional whole-strip allowance. It does not automatically add a separate spare roll; compare the result with your repair plans and the availability of the same dye lot.
Corners, damaged drops, unusable offcuts, complex openings, substrate conditions, installer layout, and match types outside the straight-match model can change material use. Confirm the product's physical dimensions, match instructions, packaging, and dye lot before ordering.
This calculator was reviewed against its production calculation logic on August 21, 2026. It estimates full-height strips for one wall or combined same-height walls, straight pattern repeat, trimming, an additional strip allowance, complete rolls, and optional paste packs. Opening area affects net area and paste only.
It does not model half-drop or offset matching, different wall heights in one run, corners, the position of openings, reusable offcuts, murals, panels, substrate preparation, labour, price, or exact installer layout. Confirm physical roll dimensions, match type, repeat, paste coverage, packaging, and dye lot on the product label. Consult an experienced wallpaper installer for complex or high-value projects.
