Skip to content
RealEstateTools

Uniform worksheet · Home Improvement

Form RET-213 · Effective August 2026 · Borrower’s copy

Wallpaper Calculator

Calculate wallpaper rolls needed based on room dimensions and roll size.

Room Dimensions

Deductions

Roll Size

Wall Area

0 sq ft

Rolls Needed

0

Coverage

0 sq ft/roll

How to Use This Wallpaper Calculator

See Methodology

Our free wallpaper calculator determines how many rolls you need based on your room dimensions, roll size, and pattern repeat. Enter your wall length, width, ceiling height, roll width, roll length, and number of windows and doors. The calculator computes gross wall area, subtracts openings, applies pattern repeat waste, and outputs the exact number of rolls needed.

How wallpaper rolls are measured. In the US, a single roll is typically 20.5 inches wide × 16.5 feet long, covering about 56 sq ft. A double roll (the more common retail unit) is 20.5 inches × 33 feet, covering about 112 sq ft. UK and European rolls differ in size — check the label. Always buy the same dye lot to avoid color variation between rolls.

Understanding pattern repeat. Patterned wallpaper requires alignment between strips. A "straight match" means the pattern repeats at the same point on adjacent strips — waste equals one repeat height. A "half-drop match" offsets the pattern diagonally, requiring up to two repeat heights of waste. A 2-inch repeat adds minimal waste; a 24-inch repeat can add 15-20% more material. The calculator factors this in based on your roll dimensions.

Wall preparation before hanging. Fill holes with spackling compound, sand smooth, and wash walls with a mild detergent solution to remove grease. Prime bare drywall with wallpaper primer — this creates a smooth surface and makes future removal easier. Never hang wallpaper on freshly painted walls (wait at least 2 weeks for paint to fully cure). Remove old wallpaper completely before applying new — new wallpaper over old causes adhesion failure.

Paste types and application. Pre-pasted wallpaper requires soaking in water to activate the adhesive. Paste-the-wall wallpaper uses a brush to apply paste directly to the wall — easier for beginners and less mess. Peel-and-stick wallpaper is self-adhesive and requires no paste — ideal for renters. Each type has different removal characteristics: peel-and-stick removes cleanly, while paste-the-wall may require steam for removal.

When to hire a professional. Professional wallpaper installation costs $1-$3 per sq ft ($200-$600 per roll). Hire a professional for: large rooms (over 400 sq ft wall area), rooms with many obstacles (cabinets, outlets, light fixtures), ceilings, or intricate patterns that require precise matching. DIY is feasible for small rooms with simple patterns — the calculator helps you buy exactly what you need.

Related Topics

wallpaper calculator ·how much wallpaper do i need ·wallpaper rolls calculator ·wallpaper cost estimator ·wall covering calculator ·

Frequently Asked Questions about Wallpaper Installation

  • How do I calculate how many rolls of wallpaper I need?

    Measure each wall's length, add them for the perimeter, and multiply by ceiling height for gross wall area. Subtract about 15 sq ft per standard window and 21 sq ft per door, then divide the net area by your roll's coverage (a US single roll covering 28 sq ft of wall, or a 20.5-inch × 33-foot bolt covering roughly 56 sq ft). Round up to the next whole roll and add 10–15% extra for waste and pattern matching.

  • How much wallpaper do I need for a 12x12 room?

    A 12x12 room with 8-foot ceilings has a 48-foot perimeter and about 384 sq ft of gross wall area, minus roughly 50 sq ft for one door and two windows — call it 335 sq ft net. That's about 6 single rolls (3 double-roll bolts) of standard 56 sq ft coverage, or 7 single rolls once you add waste allowance.

  • Should I buy single rolls or double rolls?

    US retailers almost always sell wallpaper in double rolls (bolts), even though coverage is quoted per single roll. This calculator counts whichever roll size you enter, so enter your bolt's actual width and length, then treat the result as bolts. Never mix dye lots: order every bolt for a room in the same run, noted on the label.

  • How much extra wallpaper do I need for pattern matching?

    Add 10% for plain or textured papers with no repeat. For small repeats under 12 inches, add one roll per four you buy; for large repeats over 12 inches, add one roll per two to three. Large repeats force you to drop each successive strip to realign the pattern, which throws away usable paper at the top of every strip.

  • How much does wallpaper installation cost?

    DIY: $25–$100 per roll for the paper plus $10–$30 in supplies (paste, smoother, razor blades, seam roller). Professional hanging runs $35–$100 per roll on top of materials depending on ceiling height and pattern complexity — a typical 10-roll room lands between $350 and $1,000 in labor.

  • What is the difference between peel-and-stick and traditional wallpaper?

    Peel-and-stick is a self-adhesive vinyl you can reposition and remove without tools — ideal for renters and accent walls, but seams show more on long runs. Traditional paper requires paste, levels out better over imperfect walls, and offers the widest pattern range. Both use the same roll math; just verify your roll's actual width and length on the label.

Related Line Items