A few different home improvement projects might require you to cut your countertop. For example, when you install a sink in your kitchen or bathroom, you need to cut a hole in the countertop that is the same size as the sink. When cutting a countertop, you want to take care to avoid chipping or otherwise damaging the surface. A chipped countertop can be a huge headache and very difficult to repair.
Lay masking tape around the general area where the hole needs to be cut in the countertop.
Mark the location where you plan to cut the countertop with a pencil over the masking tape.
Measure a diagonal line inward from each corner of where you intend to cut the countertop. Place a piece of masking tape on this area and mark an "X" about 1 1/2 inches from the corner.
Drill circular holes at the location of each "X" you marked. Depending on the type of countertop material, you may need to use a powerful electric drill. The larger the hole, the easier it is to cut the countertop.
Flip the countertop upside down if possible, or make the cut from underneath if it cannot be moved.
Start cutting with a jigsaw at the location of one of the holes you drilled. Use an upstroke while cutting.
Continue cutting around the countertops until you have completed all the cuts you need to make.