# What size violin, viola, cello, or bass do you need?

Source: https://arcosounds.com/guides/string-instrument-sizes
Updated: 2026-08-24

**Short answer.** Size is set by arm length and hand span, not by age or height, and it should be measured in person rather than read off a chart. For violin and viola, extend the left arm straight out with the instrument on the shoulder: the fingers should curl comfortably around the scroll without the elbow locking. For cello, sitting with the endpin set, the C-string peg should sit near the left ear and the knees should meet the lower bouts without strain.
An instrument that is too large is the most common hidden cause of a young player struggling. It produces a poor tone because the bow arm cannot reach, it forces the left hand to collapse to span the distances, it can cause genuine strain in the neck, shoulder, or thumb, and the student almost never reports it, because they assume the difficulty is their own.


## The fractions do not mean what they say

A half-size violin is nowhere near half the length of a full-size one. The names are traditional rather than proportional: the body of a 1/2 violin is about 82 per cent of a full size, and a 1/16, the smallest made, is still roughly 60 per cent. The fractions are ordinal labels, and comparing them across instrument families is meaningless.

| Instrument | Sizes made | Notes |
| --- | --- | --- |
| Violin | 1/16, 1/10, 1/8, 1/4, 1/2, 3/4, 4/4 | Most players reach 4/4 around ages 11–13, but by arm length rather than birthday. |
| Viola | Measured in inches: 12" to 16.5"+ | Violas have no standard full size, professionals play anything from 15.5" to 17". Small hands are a real constraint. |
| Cello | 1/10, 1/8, 1/4, 1/2, 3/4, 4/4 | The jump from 3/4 to 4/4 is the one most often made too early. |
| Double bass | 1/8, 1/4, 1/2, 3/4, 4/4 | 3/4 is the standard full-size orchestral bass. A 4/4 exists but is unusual. |

> **The viola exception**, Viola sizes are given in inches of body length, and there is no such thing as a full-size viola. A 15-inch and a 16.5-inch viola are both adult instruments, and the choice is a genuine trade-off: larger bodies give a deeper, more characteristic tone, and smaller ones are easier on the left hand and the shoulder. Hand span matters more here than on any other string instrument.


## How to measure

1. Violin and viola: place the instrument on the left shoulder in playing position and extend the left arm straight along the neck. The fingers should curl comfortably around the scroll with the elbow slightly bent. If the arm locks straight or the fingers cannot reach past the scroll, the instrument is too big.
2. Cello: sit on a chair with the feet flat and the endpin adjusted. The C-string peg should sit near the left ear, the top edge of the instrument should rest on the breastbone, and the knees should hold the lower bouts without the player leaning forward.
3. Double bass: standing, the nut at the top of the fingerboard should be at about eyebrow height, and the player should be able to reach first position without lifting the shoulder.
4. In all cases, have it checked at a shop or by the school orchestra director. Charts are a starting point; a two-minute in-person check is the answer.


## Signs the instrument is too big

- The left wrist collapses inward toward the neck to let the fingers reach.
- The left elbow is pushed far under the instrument, or the shoulder rides up.
- On violin or viola, the scroll droops toward the floor within a minute of playing.
- The student complains of neck, shoulder, or thumb ache, which is never normal, at any size.
- The tone is consistently poor on the lower strings, where the bow has furthest to reach.

Buying one size up "to grow into" is a false economy. A year on an oversized instrument builds a compensating technique that then has to be dismantled, and it is the most common route to a student concluding they are not musical.


## Rent while they are growing

Most children move up a size every one to two years, which makes renting the obvious choice. A rental costs a fraction of a purchase, most shops run rent-to-own schemes that credit payments toward a full-size instrument later, and the shop handles the maintenance an owner cannot judge, strings, bow rehairs, and the occasional setup adjustment.

> **On very cheap online instruments**, The problem with the cheapest online instruments is not the price; it is that they often cannot be tuned or held in tune. Bridges arrive unfitted, pegs slip, and the supplied bow will not draw a tone. A student cannot learn to play in tune on an instrument that will not stay in tune, and the resulting failure looks exactly like a lack of ability. A rental from a shop that fits and services instruments avoids all of it.


## When to size up

Re-measure roughly once a year, and after any growth spurt. The move is usually made when the current instrument has become clearly small rather than at the first moment the next size is reachable: a slightly small instrument plays well, and a slightly large one does not. Where a teacher and a shop disagree, the teacher is watching the student play, which is the better evidence.

## Frequently asked

**What size violin does my child need?**
It depends on arm length rather than age. With the violin on the left shoulder in playing position, the child extends the left arm along the neck: the fingers should curl comfortably around the scroll with the elbow still slightly bent. If the arm locks straight, the violin is too large. Have the measurement confirmed in person by a string shop or the school orchestra director.

**Is a 3/4 violin much smaller than a 4/4?**
Less than the name suggests. A 3/4 violin has a body around 335 mm against a full size at 356 mm, roughly 94 per cent of the length, not 75 per cent. The fractional names are traditional labels rather than physical proportions, which is why a size chart is no substitute for measuring.

**What size double bass is standard?**
A 3/4 bass is the standard full-size orchestral instrument, not a 4/4. Full-size 4/4 basses exist but are unusual and are chosen for specific reasons rather than as the default. Smaller fractional sizes down to 1/8 are made for young players.

**What size viola should an adult play?**
Violas are measured in inches of body length and have no standard full size; adults commonly play between 15.5 and 16.5 inches. Larger bodies give a deeper, more characteristic viola tone, and smaller ones are easier on the left hand and shoulder, so hand span and arm length decide it rather than a rule.

**Should I buy a bigger instrument for my child to grow into?**
No. A year spent on an oversized instrument builds a compensating technique, a collapsed wrist, a raised shoulder, that then has to be undone, and it frequently causes strain. Renting the correct size and moving up every one to two years costs less and works better.

Canonical source: https://arcosounds.com/guides/string-instrument-sizes