What size guitar does a 14 year old need?

Most 14 year-olds will be suited to a full-sized guitar. The average length of a full-sized guitar is between 38 and 41 inches, and the average width is between 15 and 16 inches. However, there are some 14 year-olds who may be more comfortable with a 3/4-sized guitar, which is typically between 36 and 38 inches long and 14 and 15 inches wide.

Ultimately, the best way to determine what size guitar is right for a 14 year-old is to take him or her to a guitar store and have them try out different sizes until they find one that feels comfortable.