Body Sizes, Explained

Smaller than Martin’s 0 (with a 13 1/2” lower bout), parlor guitars were designed to be comfortably played in one’s parlor or porch with a 12-fret neck. Traditionally, the parlor body is subtly elongated to enhance the volume and midrange presence.
Very small-bodied guitars whose size has been optimized for travel. Body dimensions vary, but are typically the same size or smaller than a parlor.
A lower bout of approximately 13 1/2”, 0 guitars are very small, similar to parlors, and typically has 12-fret necks.
Larger than a 0, the 00 usually has around a 14 1/8” lower bout and a 12-fret neck.

Larger than a 00, the 000 usually has a 15” or wider lower bout. The body is the same as or similar to an OM (Orchestra Model), but often with a 12-fret neck.
The size of most classical guitars, approximately 14 9/16” at the lower bout, but that measurement can vary some from builder to builder and across different styles.
OM (Orchestra Model)
The Orchestra Model, or OM, is one of the most common steel string guitar sizes, and has the same body dimensions as a 000 (15” or so at the lower bout), but with a 14-fret neck.
GC (Grand Concert)
A GC is a small to medium-size guitar with an approximately 14 3/4” lower bout, optimized for fingerstyle playing and smaller players.
Square Shoulder Dreadnought
A larger guitar, the Dreadnought is ubiquitous across the world and is one of the most common body types. The large body and projection lends itself to flat picking, but has been adapted to myriad styles. Lower bouts are approximately 15 5/8”.
Slope Shoulder Dreadnought
Very similar to a standard square-shoulder dreadnought, but the upper bout shoulders are more rounded like an OM, making the sound cavity slightly larger and enhancing the richness of the bass. Slope-shoulder dreadnoughts also occasionally come with 12-fret necks.
SJ (Small Jumbo)
A very versatile shape, the SJ has a larger lower bout around 15 1/2” or greater, and lends itself to a variety of styles. The SJ strikes a balance between even tone and projection, and often comes in 12- and 14-fret versions.
GA (Grand Auditorium)
Sort of a cross between a Grand Concert and a Dreadnought, the GA has a lower bout at 15 1/2 or 16” and has a more balanced voice than a Dreadnought.
Among the largest guitars, Jumbos have a lower bout of 16” or more and are characterized by big bass response and loud projection.
An electric guitar with a solid body without a hollow sound chamber.
Semi Hollow
An electric guitar with a partial sound chamber that features a block through the center of the body to minimize feedback.
Hollow Body
An electric guitar with a partial sound chamber which lends more acoustic color to the tone.
Designed by Lloyd Loar to satisfy Jazz guitarists’ need to compete with other instruments’ volume, archtops often feature carved tops, F holes, a floating bridge & tailpiece, and lower bouts at 15” and larger.
A style of lap steel guitar which features a hollow sound chamber that runs the length of the instrument and its neck.
Open Back Banjo
More typically suited to Old Time or traditional music, open-back banjos feature a body that consists most generally of a ring over which a fibrous material is stretched and secured in place at tension. These banjos have a warmer, mellower sound and work best in quieter environments.
Resonator or Bluegrass Banjo
Resonator banjos are, generally, an open-back banjo with a wooden “bowl” attached to the back, which reflects sound back out toward the audience. Often played with metal fingerpicks, resonator banjos tend to be brighter and louder than open-back banjos, making them the preferred type for Bluegrass and Country music.
Early banjos which feature various pot designs ranging from wooden rims to gourds, “Minstrel” banjos are usually fretless, and come in a variety of scale lengths and are generally suited to Old Time, Traditional, and 1800s Minstrel music.
A-Style Mandolin
Tear-shaped and oval-bodied, A style mandolins have fewer appointments than F styles, but are otherwise the same size, and can have either an oval soundhole or F holes. A-style mandolins are preferred for Traditional, Celtic, or Appalachian styles of music.
F-Style Mandolin
Pioneered by Gibson’s Lloyd Loar, the F-style mandolin has a lavish scroll added to the upper shoulder and several body points to the treble side, which subtly affect tone and provide a way to rest the mandolin against your leg. F-style mandolins are preferred for Bluegrass and Jazz.
Bowl Back Mandolin
Similar to traditional lutes, the bowl-backed mandolin is popular with Baroque, renaissance, and other classical styles, and has a darker, round voice due to the higher volume of its body.