PaintingWallpaper Calculator

Wallpaper Calculator

How many rolls of wallpaper do I need? Calculate rolls, strips, and paste for any room. Accounts for pattern repeat, doors, windows, and waste.

Room Dimensions

No pattern repeat waste

Ready to calculate

Enter your room dimensions

Last updated March 31, 2026 by our expert review team

Cost per Roll by Type

$/roll
Budget Vinyl$15 - $30 /roll
Mid-Range Paper$30 - $60 /roll
Premium Non-Woven$50 - $100 /roll
Grasscloth/Textured$80 - $180 /roll
Designer/Custom$100 - $300 /roll

Per double roll. Single rolls cost about half. Prices vary widely by brand and pattern.

Expert Contributors

CJ
Creator
Cherry Jane Limbago
Licensed Civil Engineer & Master Plumber
H
Expert Review
Hawkin
Certified Cost & Estimating Professional

Pro Tips

1

Always buy all rolls from the same batch/dye lot. Different batches can have subtle color differences visible when hung side by side.

2

After wallpapering, use our paint calculator to estimate trim and ceiling paint.

3

Start hanging from the most visible corner and work away from the main light source. Seams are less noticeable when lit from behind.

4

Large pattern repeats (12"+) waste 20% or more. Budget accordingly or choose a random match pattern for zero waste.

5

Use a plumb line for the first strip on every wall. Even slightly out-of-plumb starts compound across the wall.

6

Removable peel-and-stick wallpaper costs more but saves paste cleanup and is renter-friendly. Budget $40 to $80 per roll.

How the Calculator Works

1

Enter your room length, width, and wall height. The calculator computes the perimeter and total wall area.

2

Doors (21 sq ft each) and windows (15 sq ft each) are deducted. Pattern repeat and waste factor are added.

3

Total area is divided by the roll coverage to get rolls needed. Strips and paste buckets are also calculated.

Formulas

Net Area = (2 x (Length + Width) x Height) - (Doors x 21) - (Windows x 15)

Total Area = Net Area x (1 + Waste% + Pattern Waste%)

Rolls = Total Area / Roll Coverage (sq ft)

Quick Reference

Standard door
21 sq ft
Standard window
15 sq ft
US double roll
56 sq ft
Euro roll (10m)
57 sq ft
Paste per 4 rolls
1 gallon

Frequently Asked Questions About Wallpaper

How many rolls for a 12x12 room?

About 8 to 10 double rolls with standard 8-foot ceilings, 1 door, and 2 windows with 10% waste.

Single roll vs double roll?

Double rolls are standard in the US market. They have twice the length (33 ft vs 16.5 ft) and waste less per strip.

What is pattern repeat?

The distance between identical points in the wallpaper pattern. A 12-inch repeat means every 12 inches the pattern starts over. Larger repeats waste more material.

How much paste do I need?

About 1 bucket (gallon) per 4 double rolls. Pre-pasted wallpaper needs only a water tray.

Can I wallpaper over existing wallpaper?

Not recommended. Remove existing paper, repair the wall surface, prime with wallpaper primer, then hang new paper.

How do I measure for wallpaper?

Measure the perimeter of the room (all walls), multiply by ceiling height. Deduct 21 sq ft per door and 15 sq ft per window.

How many strips per roll?

A US double roll (33 ft long, 20.5" wide) yields about 3 to 4 full strips for 8-foot walls, depending on pattern repeat.

Do I need to prime walls before wallpaper?

Yes. Use a wallpaper-specific primer (not regular paint primer). It helps the paste adhere and makes future removal easier.

Wallpaper Estimates for Common Rooms

🚿

Powder Room

6x5 ft, 8 ft ceiling, 1 door, 0 windows
Rolls: 4 double rollsCost: $120-$240

Small rooms are perfect for bold patterns. With no windows to work around, hanging goes fast.

🛏️

Bedroom Accent Wall

12 ft single wall, 8 ft ceiling
Rolls: 3 double rollsCost: $90-$180

Accent walls are great starter projects. You only need to match seams on one surface.

🏠

Standard Room

15x12 ft, 8 ft ceiling, 1 door, 2 windows
Rolls: 9 double rollsCost: $270-$540

Order 1 extra roll. You will want it for future repairs, and the dye lot may be discontinued.

🛋️

Large Room

20x15 ft, 9 ft ceiling, 2 doors, 4 windows
Rolls: 12 double rollsCost: $360-$720

Tall ceilings need longer strips. Factor in extra waste for the additional height per strip.

Wallpaper Mistakes That Cost You Money

Not ordering from the same dye lot

Visible color differences between batches are common, especially with textured or natural fiber papers. Always check the lot number on every roll before buying.

Ignoring pattern repeat waste

Large patterns (12"+ repeat) waste 20% or more material per strip. Choose a random match or straight match with a small repeat to save money.

Starting with an out-of-plumb first strip

Every subsequent strip shifts further off-level. Use a plumb line or laser level for the very first strip on each wall.

Under-ordering and trying to reorder

A new batch may not match your existing rolls. Always buy 1 to 2 extra rolls up front. Most stores accept sealed returns.

Applying wallpaper to unprepared walls

Paper peels within months without proper primer. Sand glossy surfaces, fill holes, and apply wallpaper-specific primer before hanging.

Important Disclaimer

These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.