Step 1
Check the side of the bolt you are about to purchase. If the bolt has the length listed in yards, you will not need to do any conversion. If the bolt length is listed in inches, centimeters or not listed at all, move on to step two.
Step 2
Divide the length of the bolt in inches by 36. This will give you the total length in yards. If the bolt is measured in centimeters, divide the number of centimeters by 91.44. This will give you the total length in yards. If the length is not listed on the bolt, continue on to the next method.
Step 3
Roll out the entire sheet of wallpaper and lay it out flat. Take the yard stick and measure the wallpaper from end to end. Write down your calculation. This is how long your wallpaper bolt is in yards.