Rolls Needed
0
Total Area
0 sq ft
Waste Factor
0%
| Item | Value |
|---|---|
| Wall Area | 0 sq ft |
| Ceiling Area | 0 sq ft |
| Doors & Windows | 0 sq ft |
| Total Area | 0 sq ft |
| Usable per Roll | 0 sq ft |
| Pattern Waste | 0 sq ft |
| Rolls to Buy | 0 |
Wallpaper Calculator: How Many Rolls Do You Really Need in 2025?
Don’t buy too little and run out mid-wall — or too much and waste money. Our wallpaper calculator gives you exact roll count with pattern repeat, waste, doors, windows, and ceiling.
How the Wallpaper Calculator Works
Professional formula:
- Wall Area: 2 × (Length × Height) + 2 × (Width × Height)
- Ceiling: Length × Width (optional)
- Subtract: Doors (21 sq ft), Windows (15 sq ft)
- Strip Length: Wall Height + Pattern Repeat + 4" waste
- Strips per Roll: Roll Length × 12 ÷ Strip Length
- Rolls Needed: Ceiling(Perimeter ÷ Roll Width) ÷ Strips per Roll
Example: 12×10×8 ft Room, 1 Door, 2 Windows, 20.5"×33 ft Roll, 12" Repeat
- Wall Area: 352 sq ft
- Subtract: 51 sq ft → 301 sq ft
- Strip Length: 8 ft + 1 ft + 0.33 ft = 9.33 ft
- Strips per Roll: 33 ÷ 9.33 ≈ 3.5 → 3 usable
- Perimeter: 44 ft → 44 × 12 ÷ 20.5 ≈ 25.8 strips
- Rolls: 25.8 ÷ 3 = 8.6 → buy 9
Standard Wallpaper Roll Sizes
| Region | Width | Length | Coverage |
|---|---|---|---|
| US/Canada | 20.5" | 33 ft | 56 sq ft |
| Europe | 21" | 33 ft | 57 sq ft |
| UK Double | 21" | 33 ft | 57 sq ft |
| Japanese | 36" | 30 ft | 90 sq ft |
Pattern Repeat Types
- Straight Match: Pattern repeats across
- Drop Match: Offset by half repeat
- Random Match: No alignment needed
- Free Match: No waste
Waste Factors
| Repeat (in) | Waste % |
|---|---|
| 0–6 | 10–15% |
| 7–12 | 15–20% |
| 13–18 | 20–25% |
| 19–24 | 25–30% |
| 25+ | 30–40% |
Pro Tips for Perfect Wallpaper
- Buy all rolls from same batch
- Number rolls in sequence
- Start in least visible corner
- Use a plumb line for first strip
- Book wallpaper 10 mins before hanging
- Smooth from center out
- Cut with sharp blade
Tools You’ll Need
- Wallpaper paste or pre-pasted tray
- Smoothing brush or plastic smoother
- Sharp utility knife
- 4 ft level or plumb bob
- Seam roller
- Sponge and bucket
- Drop cloth
Common Mistakes
- Not accounting for pattern repeat
- Mixing dye lots
- Hanging upside down
- Not booking long enough
- Overworking paste
Wallpaper Types Guide
- Vinyl: Durable, washable, bathrooms
- Non-woven: Easy to hang/remove
- Paper: Classic, breathable
- Textile: Luxe, delicate
- Peel & Stick: Removable, renter-friendly
Cost Estimate Example
| Item | Qty | Price | Total |
|---|---|---|---|
| Wallpaper (9 rolls) | 9 | $45 | $405 |
| Paste | 1 | $15 | $15 |
| Tools | — | — | $40 |
| Total | — | — | $460 |
Related Calculators
FAQs
How many rolls for a 12x12 room? 6–8 rolls (depends on repeat).
Can I wallpaper over old wallpaper? Only if smooth and adhered.
How long does wallpaper last? 10–15 years.
Should I prime walls first? Yes — use wallpaper primer.
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