Wallpaper Quantity Calculator for Rolls & Drops
Calculate exact wallpaper rolls required — enter your wall and roll measurements to get a precise drops-per-roll specification, plain or patterned.
How would you like to work?
Wallpaper Specification
How to Use This Wallpaper Calculator
- Choose Metric or Imperial to set your working units.
- Enter your ceiling height and total wall width (add up every wall if papering a whole room).
- Choose Plain or Patterned, entering the pattern repeat if applicable.
- Enter the roll width and roll length for your chosen paper.
- Click Calculate for your total drops required, drops per roll, and total rolls to order.
Understanding Drops, Repeats and Roll Conventions
Wallpaper isn't estimated by area — it's estimated by drops, since it's sold in discrete rolls rather than a continuous length you can cut to any size. A drop is one cut length of paper running the full ceiling height, and the number of drops needed is simply the wall width divided by the roll width, rounded up.
For patterned wallpaper, each drop's cut length is rounded up to the next full multiple of the pattern repeat, so the design lines up cleanly at ceiling and floor across every drop. This is why a large pattern repeat can noticeably increase the number of rolls needed compared to a plain paper of the same height.
UK rolls are usually 10m long by 65cm wide; USA rolls are usually 7.5m long by 46cm wide and often marketed in yards. High-end and bespoke wallpapers can differ from both — always confirm the actual roll dimensions with the manufacturer.
Worked Example: A Striped Wallpaper Wall
Take a 2.4m ceiling height and a 2.5m wide wall, papered with a striped design (no complex repeat matching needed) on a standard 53cm × 10m roll. The wall width divided by the roll width gives 5 drops required. At a 250cm cut length (240cm ceiling height plus the 10cm minimum trim), each roll yields 4 drops. Five drops needed, at 4 drops per roll, comes to 2 rolls to order — matching published guidance from a well-known UK wallpaper brand almost exactly.
Frequently Asked Questions
How many rolls of wallpaper do I need?
It depends on your ceiling height, wall width, roll size, and whether the wallpaper is patterned. Wallpaper is estimated by drops per roll rather than a simple area calculation, since it's sold in discrete rolls. Use the calculator above with your own measurements for an exact roll count.
What is a wallpaper "drop"?
A drop is a single cut length of wallpaper, running from the top of the wall to the bottom, ready to hang. The number of drops needed is the wall width divided by the roll width, rounded up.
What's the difference between UK and USA wallpaper roll sizes?
UK rolls are usually 10m long by 65cm wide. USA rolls are usually 7.5m long by 46cm wide, and often marketed in yards. Always check the actual roll dimensions for your chosen paper, since high-end and bespoke wallpapers can differ from both standards.
How does pattern repeat affect wallpaper quantity?
For patterned wallpaper, the cut length is rounded up to the next full multiple of the pattern repeat, so the design lines up across the ceiling and floor. This uses more paper per drop than a plain wallpaper of the same height.
What is the minimum trim allowance for wallpaper?
A minimum of 10cm is added to the ceiling height for plain wallpaper, giving a small margin for a clean cut at the ceiling and skirting board. Patterned wallpaper doesn't need this added separately, since rounding to the next full pattern repeat already builds in a similar buffer.