Instrument Size Chart by Age and Height (2026)

Size is based on your child's height and arm length, not just age, because children of the same age vary widely. For guitar and ukulele, measure height. For violin, viola, and cello, measure the child's outstretched arm length from neck to the middle of the palm. When a measurement falls between two sizes, always choose the smaller size, because a slightly small instrument is far easier to play with correct technique than one that is too big.

No. This is the most common sizing mistake. An instrument that is too large forces a child to overstretch, which causes poor technique, hand fatigue, and discouragement. It is better to use the correct smaller size now and move up when they grow, which is exactly why renting fractional string instruments is popular. Guitars and ukuleles are inexpensive enough that buying the right size and upgrading later is usually affordable.

Young children (ages 4-6) do well on a 49 or 61-key keyboard, which covers everything in beginner method books. From about age 7, a 61-key keyboard is the practical minimum, and students serious about piano should move to a full 88-key weighted digital piano so that hand position and dynamics transfer to an acoustic piano. Key count matters more than the cabinet size for beginners.

Most children reach full-size (4/4) guitar and violin around age 11-12 when they pass roughly 5 feet tall, though tall kids get there sooner. Cello players often reach full size a little later, around ages 12-15, because the instrument is larger. Always confirm with a measurement rather than age alone, and have a teacher check the fit if you are unsure.