The primary tool for cutting acoustical ceiling panels is a sharp utility knife. The knives are available at hardware, home improvement and retail superstores as well as online. Purchase an extra pack of blades, and change your knife's blade when it becomes dull. When cutting acoustical ceiling panels, hold your utility knife at a 45-degree angle to cut a smoother edge.
Also needed to cut acoustical ceiling panels is a ruler or chalk line to ensure a straight cut. Purchase a 12-inch or longer "T-Square" or straightedge ruler. The rulers are available at hardware and home improvement stores, retail superstores and online. You can also use a chalk line to draw a straight line on the panels, but you still need a ruler to ensure a straight cut.
To speed up the cutting process, cut a piece of wood or cardboard the same size as the acoustical ceiling panel you want to install. Use this as a template, also known as a fitting board, for cutting other panels to an exact length. The template also helps to cut panels for ceilings that are an irregular size or to allow for molding you don't plan to remove from around your ceiling's edges.