Toilet seats are typically made of either wood or a hard plastic. Although they are designed to be durable and withstand extensive use as well as harsh cleaning products, they begin to show their age over time. If you have decided to replace your toilet seat, be precise as to the size you need your new seat to be. Not only does an improperly sized toilet seat look unattractive, but it is uncomfortable to use as well.
Lift up the lid of the existing toilet and note the overall shape of the seat. Toilet seats are either round or oval-shaped to match the shape of the toilet bowl.
Lift up the toilet seat and place the end of a tape measure at the front edge of the toilet bowl.
Stretch the tape measure toward the toilet tank until you reach where the seat is bolted to the toilet.
Note down the measurement at the location of the bolts to determine the length of the toilet seat needed.
According to The Fun Times Guide website, standard toilet seat sizes are 16.5 inches for round toilets and 18.5 inches for oval-shaped toilet bowls.