A perfect violin fit starts with one number: the distance from the base of your neck to the center of your palm. The three steps below turn that measurement into a reliable result, but only if you eliminate the small errors—like a bent elbow or slack in the tape—that throw off the reading. Here’s the exact protocol, using a standard tape measure, anatomical landmarks that don’t shift, and a method that catches the mistakes that cost beginners half a size or more.
What a Correct Arm Measurement Looks Like
The goal is a single number in inches that locks directly into a violin size. For adults, 23 inches or more means a full-size 4/4. For a child, 20–22 inches generally indicates a 3/4, 18–20 inches a 1/2. The measurement is taken with the arm fully extended, palm facing up, tape anchored at the sternal notch—the bony dip at the base of the neck—and read at the center of the palm. When done right, the tape lies flat against the arm with no sag or slack.
Your 3-Step Arm Measurement Checklist
- Stand with your back and heels directly against a flat wall.
- Relax both shoulders down and look straight ahead.
- Extend your right arm (or left, if you are measuring for that arm) straight out to the side at shoulder height.
- Rotate your forearm so your palm faces the ceiling.
- Anchor the zero end of the tape measure on the sternal notch—the small U-shaped depression where your collarbones meet.
- Run the tape along the top of your arm to the center of your palm, keeping the tape snug but not tight.
- Read the measurement exactly where the center of your palm meets the tape, without bending your wrist.
Step-by-Step Instructions and Common Errors
Stand Against a Wall
Position yourself with heels, buttocks, and shoulder blades touching a flat wall. This prevents the forward hunch that cuts an inch off the reading. It takes about 10 seconds. The most common mistake is standing too far from the wall so only the heels touch, which lets the upper back curve and the shoulder roll forward.
Relax Your Shoulders and Look Ahead
Drop both shoulders away from your ears and fix your eyes on a point straight ahead. Tension lifts the collarbone and shifts the sternal notch, moving the starting landmark. The pitfall is checking posture by glancing down at the tape—that head tilt re-engages the shoulder lift you just removed. Keep your head level.
Extend Arm to the Side at Shoulder Height
Lift the arm straight out until it is parallel to the floor, exactly at shoulder height. This takes about 5 seconds. The frequent error is raising the arm above the line, which stretches the tape path and gives an overly long number. Even a slight bend at the elbow collapses the distance and shortens the measurement.
Rotate the Palm Upward
With the arm still parallel, rotate the entire limb from the shoulder so the palm faces the ceiling—not just a wrist twist. This places the tape over the fleshy top of the forearm, not the outer bone, yielding a true functional length for holding the instrument. The mistake here is incomplete rotation, which measures across the side and can take off a fraction of an inch.
Anchor the Tape at the Sternal Notch
Locate the sternal notch with your free hand: it is the small dip right above the breastbone and between the collarbones. Press the metal end of the tape into that spot and hold it firm. If the zero point slips, the whole measurement is useless. The classic error is placing the tape on the throat (too high) or on the flat top of the sternum (too low), shifting the result by half an inch or more.
Run the Tape Along the Arm
Keeping the zero end fixed, run the tape along the top surface of the arm to the center of the palm. The tape must stay in contact with the skin or light clothing without sagging. Slack—even a ¼-inch loop—inflates the number. Conversely, do not pull the tape so tight that it compresses the arm tissue. The top error is allowing the tape to curve at the shoulder or drift toward the wrist. Keep the path straight.
Read the Measurement at the Center of the Palm
Read where the tape crosses the exact middle of your palm, not the wrist crease and not the base of the fingers. The center is roughly the midpoint between the middle finger base and the wrist. Do not tilt your head or bend your wrist. The most common inaccuracy comes from reading at the wrist (which shortens the measurement by 1–2 inches) or at the fingertips (which lengthens it unpredictably).
Final Verification: Did You Get It Right?
Before converting the number to a size, check each point:
- Your back, heels, and shoulders stayed against the wall.
- The tape remained flat with zero slack.
- Your head faced forward.
- The zero end never moved from the sternal notch.
- You read the number at the center of your palm.
If any point fails, re-measure. A fraction of an inch can change the violin size.
Printable Arm Measurement Cheat Sheet
Print this simplified list so the steps are always on hand:
- Stand against a wall, heels to shoulders touching.
- Relax shoulders, look straight ahead.
- Extend arm at shoulder height, palm up.
- Place tape on sternal notch (dip between collarbones).
- Run tape along arm to center of palm—keep it taut and straight.
- Read measurement at center of palm.
- Confirm: no slack, no bent elbow, no head tilt.
FAQ
Should I measure both arms?
For violin sizing, measure the left arm, as that is the one that holds the neck. Most people have nearly equal arm lengths, so measuring either side works. If there is a noticeable difference, use the arm that will support the instrument.
What if my measurement falls between two violin sizes?
Choose the smaller size. An instrument that is slightly too small is far easier to handle than one that is too large, which forces the arm to overextend and strains the shoulder. Teachers routinely recommend the smaller option.
Can I use a string instead of a tape measure?
It is possible, but a string adds two error sources: it lacks rigidity to stay straight, and you must then lay it against a ruler, which compounds inaccuracy. A flexible tape measure is the most reliable tool.
My child squirms during measurement—how can I get an accurate reading?
Have the child stand against a wall and fix their gaze on a sticker. Measure quickly. Taking two or three readings and averaging gives a more consistent result. If they cannot stay still at all, measure with the elbow bent at the side and add roughly ½ inch to the number as compensation.
Why does standing against a wall matter?
It stops the shoulder roll that happens when standing freely. That roll shortens the neck-to-palm distance and can cause you to select a violin half a size too small.
Getting the Fit Right the First Time
You now have a repeatable protocol that produces one accurate number: the inches from the sternal notch to the center of the palm with arm extended. Next time, save a few seconds by marking the center of your palm with a washable dot before starting—it removes guesswork from the final reading and makes the process automatic.
