The proper height to hang a picture:
A good rule of thumb is to hang art so that its midpoint is between 57 and 60 inches from the floor. Aim for the lower end of the range if most members of your household are on the short side; in rooms with ceilings higher than eight feet, artwork can be hung a little higher than 60 inches off the floor.
Picture hanging formula:
When hanging something at an average eye level, position its center 57 to 60 inches from the floor. Use the following formula: Divide the height of the frame by two; from that number, subtract the distance from the top of the frame to the hanging hardware; add this number to 57, 58, 59, or 60.
The easiest way to hang a picture level:
Here's the trick: For a frame with two brackets on the back, place a piece of painters tape across the back. Mark on the tape exactly where the nails or screws need to go. Take your marked tape and place it on the wall where you want your pictures to hang.