Things You'll Need
Wood drill bit set
Hole saw bit set
Compass and pencil
A variety of tools are at your disposal to cut circular holes in wood. Depending on the size of the hole you wish to drill, you can use either a standard drill bit for holes ranging from extremely small to about 1 inch in diameter. You can use a hole saw to cut out a circular section of wood ranging in size from about 3/4 to 3 inches in diameter. For anything bigger, you must use a jigsaw after first drawing the circle you wish to cut out.
Obtain a drill bit with the diameter of the hole you wish to cut, either in inches or millimeters. For holes ranging from extremely small to 1 inch, look for a matching bit and insert it into the chuck at the tip of the drill. Match three of the six flat sides at the opposite end of the bit from the cutting tip with the three teeth in the chuck that grip the bit. Tighten it to the drill using the chuck key, or hand tighten it if using a keyless chuck. Start the drill, and push the spinning bit into the wood at a perpendicular angle to cut the hole.
Obtain a matching size hole saw bit if cutting a hole with a diameter between 3/4 inch and 3 inches. Hole saws have a serrated edge around the circumference only, allowing them to cut through wood more easily. The saw only cuts the outside edge of the hole, meaning less resistance for the bit. Place the tip of the bit inside the hole saw at the center of your desired hole, then start the drill and press it evenly into the surface of the wood to cut the hole.
Draw a circle onto your piece of wood using a compass and a pencil if the circle needs to be larger than 3 inches in diameter. Set the compass to half the diameter of the desired hole measured between the tip of the compass and the tip on the pencil, then place the tip of the compass at the center of your desired hole and draw a circle around it with the attached pencil. Drill a 1/2-inch-diameter hole using a standard drill bit inside the drawn-on hole, then insert the blade of your jigsaw through the hole and cut out the circle along the drawn-on line.
Use a drill press if possible to ensure you drill straight holes.
Always wear protective eyewear when operating power tools.