That’s easy. Just use our Wallpaper Calculator.
Since your starting and stopping point is the only place in the room that is unlikely to match, it is important to start your job in the least visible corner of the room. A good place to start is usually in the corner that is closest to the entryway.
Depending on type, wallpaper can expand its width up to 1/4 inch. To avoid expansion on the wall, which can cause bubbling and wrinkles, it is necessary to “book” the paper before hanging. “Booking” means folding the paper onto itself for several minutes, paste-to-paste, to allow the paper to relax before applying to the wall. Book un-pasted paper immediately after applying paste. This allows the paper to fully expand, relaxing its curl.
Primer is a protectant/sealer for your wall which prevents the paste from absorbing into porous surfaces, and allows the paste to grip on slick surfaces. Many products on the market today are a combination sealer/sizer; these one-step universal wallcovering primers are easier to use and are formulated to work on a variety of surfaces under varying conditions. Sealing the surface is also an important procedure to allow for future removal.
The pattern match and repeat affect the hanging method, the waste amount and the total amount of paper needed for a job. Generally speaking, the larger the repeat, the greater the chance for waste, but a drop match of the same repeat would have less waste than a straight match.