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Wallpaper Calculator

Estimate wallpaper rolls and cost with trim/waste allowance and optional pattern repeat.

Results

Wall area (sq ft)
486.00
Area minus openings (sq ft)
486.00
Area with waste (sq ft)
534.60
Strips needed
32.00
Rolls needed
11.00
Estimated cost
$495

How to use this calculator

  1. Enter room length, width, and wall height.
  2. Optionally subtract door/window square footage.
  3. Enter roll width, roll length, pattern repeat, and waste allowance.
  4. Add cost per roll to see a budget estimate.

Inputs explained

Room length/width
Dimensions of the room. For multiple rooms or accent walls, calculate separately.
Wall height
Finished height in feet. Include any crown/baseboard if it affects drop length.
Openings (sq ft)
Door/window area to subtract if you want a tighter estimate.
Roll width/length
Wallpaper roll dimensions; adjust if using double rolls.
Pattern repeat
Add the repeat to each drop to maintain pattern alignment.
Waste/trim allowance
Extra coverage for trimming, matching, and offcuts around corners.
Cost per roll
Enter your supplier price to estimate project cost.

How it works

We use room perimeter × height for wall area, subtract optional openings, then add a waste allowance.

Strips needed = perimeter ÷ roll width; strips per roll = floor(roll length ÷ (wall height + repeat)). Rolls = strips ÷ strips-per-roll.

Formula

Perimeter = 2 × (Length + Width)
Wall area = Perimeter × Height
Adjusted area = Wall area − Openings
Area with waste = Adjusted area × (1 + Waste%)
Strips needed = Perimeter ÷ Roll width(ft)
Strips per roll = floor(Roll length ÷ (Height + Repeat))
Rolls = ceil(Strips ÷ Strips per roll)
Cost = Rolls × Cost per roll

When to use it

  • Sizing rolls for full-room installs with doors and windows.
  • Estimating accent wall coverage without overbuying.
  • Comparing single vs double rolls and pattern repeats on total rolls required.

Tips & cautions

  • Round up rolls to cover pattern matching and miscuts—returns are easier than running short mid-wall.
  • If using double rolls, set roll length to twice the single-roll length; width usually stays the same.
  • Pattern repeats increase drop length; confirm repeat from the manufacturer before ordering.
  • Assumes rectangular rooms; odd shapes or niches need section-by-section math.
  • Strips-per-roll uses floor division—short drops reduce usable strips; always round up rolls.
  • Does not include adhesive, lining paper, or labor.

Worked examples

15×12 room, 9 ft height, 10% waste, 20.5" × 33 ft roll

  • Perimeter = 54 ft; Wall area = 486 sq ft
  • Adjusted area (no openings) = 486 sq ft; with waste ≈ 534.6 sq ft
  • Strips needed ≈ 32 (54 ÷ 1.708 ft)
  • Strips per roll ≈ floor(33 ÷ 9) = 3
  • Rolls ≈ 10.7 → round up to 11

Accent wall 14 ft wide × 9 ft high, 8% waste, 27" × 33 ft roll, 2" repeat

  • Perimeter for strips ≈ 14 ft; Wall area = 126 sq ft; with waste ≈ 136.1 sq ft
  • Strips needed ≈ 7 (14 ÷ 2.25 ft)
  • Drop length = 9 + 0.167 ft ≈ 9.167 ft
  • Strips per roll ≈ floor(33 ÷ 9.167) = 3
  • Rolls ≈ 2.34 → round up to 3

Deep dive

This wallpaper calculator turns room dimensions and roll specs into rolls needed with a built-in waste buffer and optional pattern repeat.

Use it to avoid under-ordering: enter length, width, height, roll width/length, and repeat to see strips, rolls, and cost.

FAQs

Do I need to account for pattern repeat?
Yes—add the repeat so each strip lines up. Larger repeats increase drop length and reduce strips per roll.
Single vs double rolls?
Double rolls are usually twice the length. Update roll length to the double-roll length; width stays the same.
How much waste should I add?
10–15% is common to cover trimming, pattern matching, and offcuts. Increase for complex patterns or many openings.
Can I subtract doors and windows?
Yes—enter their total square footage to tighten the estimate. Still keep a waste buffer.
Does this include adhesive or labor?
No. Add paste, lining paper, and labor separately to your budget.

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Estimates only. Confirm roll sizes, repeats, and coverage with your wallpaper supplier and installer before ordering.