Wallpaper Calculator
Wallpaper Calculator: How Many Rolls Do You Need?
Ordering too little wallpaper means stopping mid-room to hunt for a matching roll — and if the pattern is discontinued or comes from a different batch, the dye lot won’t match. Ordering too much wastes money on material you can’t return. The wallpaper calculator solves both problems. Enter your room dimensions, ceiling height, doors, windows, and pattern repeat, and get an accurate roll count before you order a single strip.
This guide explains the full wallpaper calculation formula, covers pattern repeat, and answers every common question about measuring for wallpaper.
How to Calculate How Much Wallpaper You Need
Basic Wallpaper Formula (No Pattern Repeat)
Step 1 — Calculate total wall area
Wall Area = Perimeter × Ceiling Height
For a rectangular room:
Perimeter = 2 × (Length + Width)
Step 2 — Subtract doors and windows
- Standard door: ~20 sq ft (2 ft wide × 7 ft tall = 14 sq ft — use 20 sq ft for trim overage)
- Standard window: ~12–15 sq ft
Step 3 — Divide by usable roll coverage
Rolls = Net Wall Area ÷ Usable Coverage Per Roll
Step 4 — Add 10% waste allowance
Rolls to Order = Calculated Rolls × 1.10 (round up to nearest whole roll)
Worked Example: 12×12 Room
- Perimeter: 2 × (12 + 12) = 48 ft
- Wall area: 48 × 9 ft ceiling = 432 sq ft
- Subtract 1 door (20 sq ft) + 2 windows (28 sq ft) = 384 sq ft net
- Usable coverage per double roll: 56 sq ft
- Rolls: 384 ÷ 56 = 6.86 → round up = 7 double rolls
- With 10% waste: 7.7 → order 8 double rolls
Understanding Wallpaper Roll Sizes
Wallpaper pricing is confusing because books list prices per single roll, but most wallpaper is manufactured and sold in double rolls. A single roll provides only about 13.5 running feet — enough for one 8–9 foot strip — while a double roll gives approximately 27 feet, enough for 3 full strips.
| Roll Type | Width | Length | Coverage |
|---|---|---|---|
| American single roll | 27 inches | 13.5 ft (4.5 yds) | ~28–30 sq ft |
| American double roll | 27 inches | 27 ft (9 yds) | ~56–60 sq ft |
| European single roll | 20.5 inches | 33 ft (11 yds) | ~56 sq ft |
| European double roll | 20.5 inches | 66 ft (22 yds) | ~112 sq ft |
| UK standard roll | 52 cm (~20.5″) | 10 m | ~5.2 m² |
| UK wide roll | 68 cm | 10 m | ~6.8 m² |
Single rolls typically cover 28 to 30 square feet, while double rolls cover 56 to 60 square feet. Always confirm the roll dimensions on the packaging before calculating — coverage varies significantly between suppliers.
How Many Yards of Wallpaper Do I Need?
US wallpaper yardage is calculated in linear yards (the length of the roll):
Linear Yards Per Roll = Roll Length in Feet ÷ 3
For a standard US double roll (27 ft): 27 ÷ 3 = 9 yards
How many yards for a room:
Total Yards = Number of Strips × Strip Length in Yards (including repeat allowance)
For a 12×12 room needing 16 strips at 3.25 yards each (9.75 ft for an 8 ft wall with repeat):
16 × 3.25 = 52 yards total 52 ÷ 9 yards per double roll = 5.8 → order 6 double rolls
Wallpaper Yards Calculator Quick Reference
| Room Perimeter | 8 ft ceiling | 9 ft ceiling | 10 ft ceiling |
|---|---|---|---|
| 40 ft (10×10) | 5–6 double rolls | 6–7 double rolls | 7–8 double rolls |
| 48 ft (12×12) | 7–8 double rolls | 8–9 double rolls | 9–10 double rolls |
| 56 ft (12×16) | 8–9 double rolls | 9–11 double rolls | 10–12 double rolls |
| 68 ft (16×18) | 10–12 double rolls | 11–13 double rolls | 13–15 double rolls |
Wallpaper with Pattern Repeat: The Critical Adjustment
Pattern repeat is the most important variable in wallpaper calculation. It’s the vertical distance between where a pattern begins and where it begins again. Large repeats waste significant material — and your wallpaper calculator must account for this.
How Pattern Repeat Affects Strip Length
Adjusted Strip Length = Ceiling Height + Pattern Repeat
Example: 9 ft ceiling, 18-inch pattern repeat:
9 ft + 1.5 ft = 10.5 ft adjusted strip length
This means instead of cutting 3 strips from a 27-ft roll, you may only get 2.
Types of Pattern Match
| Match Type | Waste Factor | Description |
|---|---|---|
| No match (random/plain) | 0–5% | Stripes, solids, random textures |
| Straight match | 10–15% | Pattern aligns horizontally across strips |
| Half-drop match | 15–25% | Pattern offsets by half a repeat on adjacent strips |
| Drop match (offset) | 20–30%+ | Most complex, highest waste |
Normally, wallpaper without a drop-pattern covers 29 to 36 square feet per roll. However, with a drop-pattern of 19 to 23 inches, you may only cover 15 square feet per roll — which makes a substantial difference in how many rolls you need to order.
Pattern Repeat Calculation Formula
Number of usable strips per roll:
Strips Per Roll = Roll Length ÷ Adjusted Strip Length
Rolls needed:
Rolls = Number of Strips Required ÷ Strips Per Roll (round up)
Number of strips for a room:
Strips = Room Perimeter ÷ Roll Width (round up)
Wallpaper Square Footage Calculator
To calculate square feet needed for wallpaper:
Total Wall Sq Ft = Perimeter × Ceiling Height − (Doors × 20) − (Windows × 12)
Square Footage by Room Size
| Room | Perimeter | 8 ft ceiling | 9 ft ceiling |
|---|---|---|---|
| 10×10 | 40 ft | 320 sq ft | 360 sq ft |
| 12×12 | 48 ft | 384 sq ft | 432 sq ft |
| 12×15 | 54 ft | 432 sq ft | 486 sq ft |
| 14×18 | 64 ft | 512 sq ft | 576 sq ft |
| 10×8 (bathroom) | 36 ft | 288 sq ft | 324 sq ft |
Subtract approximately 32–40 sq ft for a standard door, 15–20 sq ft per window. Always leave at least 10% extra for trimming and matching.
Wallpaper for One Wall: Accent Wall Calculator
For a single accent wall, the calculation simplifies to:
Wall Sq Ft = Wall Width × Wall Height
Rolls = Wall Sq Ft ÷ Usable Roll Coverage × 1.10
Example: Accent wall 12 ft wide × 9 ft tall = 108 sq ft
With a 12-inch pattern repeat (adjusted height = 10 ft):
- Strips needed: 12 ft ÷ (27″/12) = 5.3 → 6 strips
- Strips per double roll: 27 ft ÷ 10 ft = 2.7 → 2 full strips
- Rolls: 6 strips ÷ 2 strips/roll = 3 double rolls
For a plain or random match wallpaper: 108 ÷ 56 = 1.93 → 2 double rolls (much less waste without pattern matching).
How Much Extra Wallpaper to Order
Purchase 20% more wallpaper than your wall’s square footage to account for the waste from cutting, pattern matching, and to have some left for future repairs.
As a practical guide:
- No pattern or random match: add 10%
- Small pattern repeat (under 6 inches): add 10–15%
- Medium repeat (6–18 inches): add 15–20%
- Large repeat (over 18 inches) or half-drop match: add 20–30%
Always buy from the same batch/lot number. Even small dye variations between lots are visible on the wall.
Wallpaper Installation Cost Calculator
Professional wallpaper installation costs $4 to $10 per square foot, including both materials and labor. Most homeowners spend between $325 and $825 for a standard room, with an average around $600.
Cost Breakdown Per Square Foot
| Component | Low | Mid | High |
|---|---|---|---|
| Wallpaper materials | $0.50/sq ft | $1.50/sq ft | $5.00+/sq ft |
| Installation labor | $1.00/sq ft | $3.50/sq ft | $7.00/sq ft |
| Total installed | $1.50/sq ft | $5.00/sq ft | $12+/sq ft |
Wallpaper Cost by Type (Per Roll, Material Only)
Single rolls typically cover 28 to 30 square feet, while double rolls cover 56 to 60 square feet. Wallpaper costs $20 to $250+ per roll depending on the material.
| Type | Price Per Roll | Notes |
|---|---|---|
| Basic paper / non-woven | $18 – $40 | Easy to hang and remove |
| Peel-and-stick vinyl | $20 – $50 | DIY-friendly, renter option |
| Vinyl-coated | $35 – $80 | Most popular, washable |
| Woven / fabric-backed | $60 – $140 | Textured look, harder to hang |
| Grasscloth | $80 – $140 | Natural fiber, statement piece |
| Foil / metallic | $75 – $120 | Dramatic effect, delicate |
| Luxury / designer | $150 – $500+ | Farrow & Ball, Sanderson, York |
| Custom mural / Spoonflower | $5+/sq ft | Printed to measure |
Wallpaper Cost by Room
| Room | Approx. Wall Area | Materials (mid-range) | Installed (mid-range) |
|---|---|---|---|
| Small bathroom (5×8) | 150 sq ft | $200 – $400 | $750 – $1,500 |
| Bedroom (12×12) | 380 sq ft | $400 – $800 | $1,500 – $3,000 |
| Living room (15×20) | 600 sq ft | $600 – $1,200 | $2,400 – $5,000 |
| Accent wall only | 80–120 sq ft | $100 – $300 | $400 – $1,000 |
Unit Conversion Reference
Our wallpaper calculator accepts input in centimetres, metres, inches, feet, and yards. Here’s a quick reference for converting between units:
| From | To | Multiply By |
|---|---|---|
| Centimetres (cm) | Metres (m) | ÷ 100 |
| Metres (m) | Inches (in) | × 39.37 |
| Inches (in) | Feet (ft) | ÷ 12 |
| Feet (ft) | Yards (yd) | ÷ 3 |
| Square metres (m²) | Square feet (ft²) | × 10.764 |
| Square feet (ft²) | Square yards (yd²) | ÷ 9 |
| Square inches (in²) | Square feet (ft²) | ÷ 144 |
Frequently Asked Questions
How Do I Calculate How Much Wallpaper I Will Need?
Measure the room perimeter (2 × length + width), multiply by ceiling height for total wall area, subtract doors and windows, divide by the usable coverage per roll (typically 56 sq ft for a double roll), add 10–20% for waste, and round up to the nearest whole roll. Use our wallpaper calculator above to handle the pattern repeat automatically.
How to Do the Math for Wallpaper?
Wall Area (sq ft) = Perimeter × Ceiling Height. Subtract 20 sq ft per door and 12 sq ft per window. Divide by usable roll coverage. For pattern repeat, calculate adjusted strip length = ceiling height + repeat, then find strips per roll = roll length ÷ adjusted strip height. Multiply strips needed by adjusted strip length to get total linear footage, then divide by roll length.
How Many Feet Does One Roll of Wallpaper Cover?
A standard US double roll covers 56 to 60 square feet at roughly 27 ft of length. A European single roll covers approximately 56 square feet at 33 ft of length. With a large pattern repeat (18″+), usable coverage drops to 30–40 sq ft per double roll due to waste from pattern matching.
How Much Will 200 sq ft of Wallpaper Cost Approximately?
At mid-range pricing of $1.50/sq ft for materials, 200 sq ft of wallpaper costs approximately $300 in materials. That’s about 4 double rolls at $75 each. Add professional installation at $3.50–$5/sq ft and your total rises to $1,000–$1,300 for a 200 sq ft wall area installed.
How Much Does It Cost to Wallpaper a 12×12 Room?
A 12×12 room with 9-foot ceilings has approximately 380–430 sq ft of wall area. Most homeowners spend between $325 and $825 for a standard room, averaging around $600. For a 12×12 room, mid-range wallpaper (materials + professional installation) typically runs $1,500–$3,000 depending on the wallpaper type and finish complexity.
What Is the Price of 100 Square Feet of Wallpaper?
Materials only: 100 sq ft at $1/sq ft (budget) = $100; at $2–3/sq ft (mid-range) = $200–$300; at $5+/sq ft (designer) = $500+. Professionally installed, 100 sq ft costs $400–$1,000 including labor and materials. Labor alone runs $3 to $7 per square foot, so for 100 sq ft expect $300–$700 in installation costs on top of the material price.