Sizes vary from
1/4-size to full-size. A full-size classical guitar has a smaller
body than a full-size steel-string acoustic guitar. Full-size -- the most common size for adults. Usually,
13- or 14-year-olds are ready for a full-size guitar. 3/4-size -- appropriate for 10- to 13-year-olds
or smaller adult players. Smaller sizes -- excellent for getting youngsters
started. These ages are only a guideline and vary from person
to person.
Since you're going to be spending a lot of time with
your guitar, it must fit
comfortably in your hands and against your body.
When trying a guitar, sit down and hold it on its side in
your lap. You should be able to easily reach the sound
hole with one hand and the tuning machines with the other
hand at the same time. Stretching to reach won't make for
smooth playing, and the guitar is not suitable for you.