To hang a wall-mounted oversized clock, choose a location with a stud. Center the clock on the stud, and move it up and down to determine the height. Make a pencil mark on the wall on the top center of the clock; straight down from this point, make a second mark at the height of the hanging bracket. Insert a screw or a hook into the wall at the lower mark, and hang the clock.
The hanging hardware you choose depends on the clock design. If the clock has a raised keyhole mounting bracket, choose a screw that is larger than the narrow end of the keyhole. Keyhole brackets that sit below the rim of the clock also accept hooks.
When hanging heavy clocks, choose a hook or screw that is long enough to run through the drywall and at least 1/2 inch into the stud. Longer hooks provide more stability.
If there are no studs near your chosen location, use a drywall anchor or a heavy-duty picture hanger to hang the clock. Weigh the clock, and choose hanging hardware that is rated to hold a heavier weight. If your clock weighs more than 25 pounds, do not hang it on drywall; the heavy load can pull out the anchor and leave a hole in the wall.