Free Online Wallpaper Calculator

About Wallpaper Calculator

Wallpaper is sold in rolls of fixed width and length, and figuring out how many rolls a room needs means working through two separate divisions: how many vertical strips fit around the room's perimeter, and how many of those strips one roll can yield based on wall height — a calculation that's easy to get subtly wrong by hand.

This calculator takes your room's length and width to compute total wall perimeter, divides that by your wallpaper roll's width to get the number of strips needed, then separately divides the roll's length by your ceiling height to see how many strips each roll yields, before combining both numbers into a final roll count.

Default roll dimensions (21 inches wide, 33 feet long) match a standard US single roll, but you can adjust both values to match the specific wallpaper product you're using — European rolls, for instance, commonly use different width and length standards.

How it works

1. Enter room dimensions. Input the room's length, width, and ceiling height in feet.
2. Enter roll specifications. Input your wallpaper roll's width in inches and length in feet.
3. See the roll count. View strips needed, strips per roll, and total rolls to buy.