Wallpaper Calculator for an Accurate Roll Count
This wallpaper calculator tells you exactly how many rolls you need from your room dimensions, doors, windows, roll size, and pattern repeat. Buy too few and you risk a mismatched batch; buy too many and you waste money.
Instead of a rough area estimate, it uses the strip-based method that professional decorators rely on — counting the vertical strips around your walls and how many fit per roll. It is built for anyone planning a feature wall or a whole-home project, whether your wallpaper is a plain solid, a straight match, or a tricky half-drop pattern.
How to Use the Wallpaper Calculator
Enter room dimensions
Measure your room's length, width, and height and type them in. Switch between Metric (m) and Imperial (ft) at any time — values convert automatically.
Add doors and windows
Tap a preset for a standard Door, Double Door, Window, or Large Window, or use Add Custom Opening for non-standard sizes. Adjust the quantity for identical openings — their area is subtracted from the walls.
Configure your wallpaper
Pick a roll size — Standard (0.53m), Wide (0.70m), Double (1.06m), or Custom — then choose the pattern match: None, Straight, or Half-Drop. For a patterned design, enter the pattern repeat distance from the wallpaper label.
Review the result
See the rolls needed instantly, plus a breakdown of total wall area, openings area, net area, strips needed, strips per roll, and effective strip height. Drag the Waste Factor slider (5–20%) to add a margin for cutting and mistakes.
Add more rooms (optional)
Use the room tabs to add each room with its own dimensions and openings. The All Rooms Summary shows a grand total of rolls across your whole project, and the cost estimate updates as you go.
Features
Strip-Based Calculation
Counts the vertical strips around your room and how many fit per roll for an accurate count area-only estimates miss.
Flexible Roll Sizes
Choose Standard 0.53m, Wide 0.70m, or Double 1.06m presets, or enter a custom roll width and length.
Pattern Match Support
Handles None, Straight, and Half-Drop matches, adding the extra material that aligned patterns require per strip.
Adjustable Pattern Repeat
Enter the repeat distance from the wallpaper label so each strip is cut to the nearest full repeat.
Door & Window Openings
Subtract doors and windows with one-tap presets or custom sizes, and set a quantity for identical openings.
Waste Factor Slider
Dial in a 5% to 20% allowance for trimming, mistakes, and a spare roll from the same batch.
Metric & Imperial Units
Toggle between meters and feet at any time, with all dimensions and pattern repeat converting live.
Multi-Room Planning
Add a tab per room, each with its own dimensions and openings, to plan an entire home in one session.
All-Rooms Summary
A summary lists rolls per room and a grand total so you know exactly how much to order.
Cost Estimator
Enter the price per roll and the estimated total cost updates automatically as your settings change.
Detailed Breakdown
See total wall area, openings area, net area, strips needed, strips per roll, and effective strip height.
Auto-Saved Preferences
Your rooms, units, roll, and settings are remembered in your browser, ready when you return.
Frequently Asked Questions
How much wallpaper do I need for a room?
Enter the room's length, width, and height, add any doors and windows, then pick your roll size and pattern match. The calculator works out the wall strips, fits them into rolls, applies your waste factor, and shows the number of rolls needed — with a full breakdown of areas and strips.
How many rolls of wallpaper for a 10x10 or 12x12 room?
It depends on the ceiling height, roll width, and pattern repeat, so there is no single fixed number. Enter your exact 10×10 or 12×12 dimensions and ceiling height and the calculator gives a precise count for your wallpaper instead of a rough guess. A taller ceiling or a large pattern repeat increases the rolls required.
How does pattern repeat affect the amount?
Pattern repeat is the vertical distance before a design repeats, listed on the wallpaper label. With a match, each strip is cut up to the next full repeat, so a larger repeat wastes more per strip. A half-drop pattern offsets every other strip by half the repeat and typically uses 10–15% more wallpaper than a straight match.
How much area does one roll cover?
A standard roll is 0.53m wide and 10.05m long, giving roughly 5.3m² of paper — but usable coverage is lower because each strip is cut to the wall height plus a trim allowance, and patterned papers lose more to matching. The result panel shows the strips per roll for your exact setup so you see real coverage, not just the raw roll area.
Should I subtract doors and windows?
Yes — subtracting openings gives a more accurate estimate, and the presets make it quick. If a room has many small windows, cutting around them creates extra offcuts, so you may prefer to keep the openings but raise the waste factor to 15–20% to stay covered.
How much extra wallpaper should I buy?
A 10% waste factor works for simple rooms with plain wallpaper. For patterned papers or rooms with many corners, alcoves, or openings, set the slider to 15–20%. It is always better to have a spare roll than to reorder from a different batch, which can have slight color variations.
Which roll size should I choose?
Standard (0.53m × 10.05m) is the most common worldwide. Wide (0.70m) rolls are popular in some European countries, and Double (1.06m) rolls cover walls faster with fewer seams but are heavier to handle. Always check your wallpaper's packaging and use the Custom option if your roll differs.
Is the calculation accurate?
The strip-based method matches how professional installers plan a job and captures the pattern-repeat waste that area-only calculators ignore. For the best result, measure carefully, set the right pattern match and repeat, and keep a sensible waste factor as a safety margin.
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