How to size your instrument – Violin, Viola + Cello

Welcome to the wonderful world of string instruments!  You’re probably a little overwhelmed at all the information you need to know in order to get the perfect instrument for your beginning student.  Here at Day Violins, we understand!  As parents of students, we’ve been right where you are at.  This sizing guide will help you ensure that your child has the correct instrument to allow them to succeed in learning to play!

A correctly sized instrument is critical to your child’s music experience.  If the instrument is too big or too small it is very difficult or even impossible to play.

If possible, the very best way to size an instrument is to come see us at our shop!  We will do all the hard work in determining the correct size and help you pick out the perfect instrument.  Or, have your child’s orchestra teacher size your child and tell you the proper instrument size to rent.  If neither of these options are available to you then read on to understand exactly how to find the perfect instrument for your student player!

Use the charts below to help guide you as you determine the proper size of instrument.  Don’t hesitate to contact us with any questions!


The measurement for Violin and Viola is made of your child’s arm length.  To take the arm measurement:

  1. Have your child stand upright, with their left arm extended to the side, with their palm turned upward.
  2. Place the end of the ruler against your child’s neck
  3. Extend the ruler down your child’s arm to the middle of their palm
  4. Take the measurement to the middle of the palm
  5. Compare the measurement to the chart to determine the correct size. The chart gives a length range that is appropriate for each size.
  6. If the measurement is “close, but not quite…” chose the smaller size. It is easier to play and learn on an instrument that is smaller rather than on one that is too big.

(Note:  All measurements are in Inches)


Arm Length   Violin Size 

Under 14 ½”      1/32

14 ½”  to 16”      1/16

16”  to  17 ¾”     1/10

17 ¾”  to 19“       1/8

19”  to  20 ¾”      1/4

20 ¾”  to  22”      1/2

22”  to  23 ½”      3/4

23 ½” or Over     4/4


Arm Length    Viola Size

19”  to  20 ¾          11”

20 ¾”  to  22”         12”

22”  to  23 ½”         13”

23 ½”  to  25 ½”     14”

25 ½”  to  26 ¼”     15”

26 ¼”  to  27”        15.5”

27”  to  27 ½”         16”

27 ½” and longer  16.5”


Correctly sizing a cello is a little more difficult.  Cello sizing is determined by a combination of measurements.  A combination of the following charts may be used as a guide to determine the correct size cello for your child


Height is standing height measured with feet flat on the floor.

Inst. Size    Height            

1/8         48” to 50”

1/4        50” to 54”

1/2        54” to 58”

3/4       58” to 62”

4/4      62” or Over


Left Arm Length is measured with the left arm extended straight to the side.  The measurement is taken from the point of the shoulder to the tip of the middle finger.

Inst. Size   Left Arm

1/8          Under 18”

1/4          18” to 20”

1/2          20” to 22”

3/4         22” to 24”

4/4         24” or Over


Left-hand finger width is taken with the left-hand fingers spread wide.  The measurement is taken from the outside tip of the index finger to the outside tip of the pinky finger.

Inst. Size   Left Hand 

1/8         Under 3”

1/4         3” to 4”

1/2         4” to 5”

3/4         5” to 6”

4/4         6” or Over


Knee to ear measurement is taken sitting on the front edge of a chair, feet flat on the floor, upper legs parallel with the floor, knees spread to cello width, and back straight.  The measurement is taken from the inside of the right knee to the opening of the left ear.

Inst. Size   Knee/Ear 

1/8         Under 23.5”

1/4         23.5” to 25.5”

1/2        25.5” to 27.5”

3/4        27.5” to 30”

4/4        30” or Over

As you can see, the measurements for properly sizing a cello are complex The most important of the four given measurements is “Left-Hand Finger Width”.   If the left-hand finger width is not adequate, drop to the next lower instrument size until the left-hand finger width measurement is adequate.   However, please do not “oversize” the instrument based on a proportionally larger left-hand finger width.

If you have any questions or are unsure if you are doing the measurements correctly, feel free to contact the professional staff at Day Violins for assistance at





Welcome new parents!

Welcome new parents