Sizing Guide

Find Your Proportion: The Ergonomic Fit

At Proportion Guitars, we don’t believe in sizing guitars based on a child's age. Every child grows differently, and a guitar that is even a few centimeters too big can lead to physical strain and technical frustration.
To find the perfect instrument for your student, we recommend using these two physical benchmarks.

The Belly Button Rule (Guitar Size)

This is the most accurate way to ensure that the the guitar isn't too large for the student's torso.

  • The Test: Stand the guitar on the floor vertically next to the student.
  • The Goal: When standing the guitar on its end, the top should be level with the child's belly button. Simply measure the distance from the floor to their navel; if the measurement is 36", a 36" model will provide the most comfortable reach and posture.
  • Why it matters: If the guitar is too large, the student’s left arm will have to reach higher above their shoulder and their right arm will have to extend around the lower bout to reach of the strings, which could cause physical strain a fatigue. Additionally, a larger guitar may feel like it’s sliding away because the player can’t get a secure grip on the body.
    If playing hurts or sounds bad, the student is more likely to quit. 

The Elbow Test (Scale Length)

Once you have determined the guitar size is correct, use the Elbow Test to ensure the neck (scale length) is appropriate for the student's arm reach.

  • The Test: Have the student place their elbow at the top edge of the guitar body (where the neck meets the body) and extend their arm straight along the side of the neck.
  • The Goal: Their wrist should reach between the first and second fret.
  • Why it matters: If the student's wrist is far below the second fret, the neck is too long. Technique will suffer as the small hands struggle to reach across the frets and strings will get muted because the fingers can’t hold the proper arch. This can lead to discomfort, poor finger alignment, and frustration.

What if I can’t find the right size?

If a child is between sizes, we always recommend choosing the smaller instrument. A slightly smaller guitar allows for a relaxed posture and the development of good habits and proper technique. A guitar that is too large forces the child to accommodate to the instrument limiting their range of motion.