Side note: Wallpaper is in a slightly larger scale than fabric and gift wrap. The design on fabric will repeat about every 3 inches. On wallpaper it will repeat every 4.
Wallpaper Coverage Calculator
Based on the dimensions you provide, this calculator will determine the number of custom-length sections of paper you'll need to cover any surface. If the height of your surface varies, input the tallest dimension in order for the pattern to line up correctly.
Enter your dimensions in feet (1 foot is 30.48 cm).