My daughter teaches guitar (acoustic and electric) and bass guitar. Until now her pupils have arrived with appropriately sized instruments - most have been adults and teenagers. She has also played violin since she was four.

She writes:
"You know with violins, you can estimate the match between violin and person-arm-length by the person putting their hand around the scroll?

I want to find out what the equivalent test is for guitar size. I had a young pupil turn up with a guitar I could tell was too big for her, and I'd like to be able to tell her Mum how to recognise the right size when they go shopping."

She would be very grateful for help on this one and I'll pass on any suggestions.

i don't think there's a similar test - it's probably a question of getting something that feels comfortable for the child. When the child sits with the guitar in the proper position (classical, I mean here) they should have the guitar resting comfortably at a slight angle on their knee, with the back of the guitar against their chest. In this position, their right arm should rest on the bottom curve of the guitar wth their forarm resting so that the guitar rim is on the forearm, just below the elbow. In this position, the wrist should curve upwards slightly, with the hand at a comfortable angle beneath the wrist. (i.e. the hand shouldn't flex backwards, and the wrist shouldn't collapse).

Bear in mind that there are often significant tuning problems with the very small ones.

Many thanks for the description Meerkat, I'll pass that on. I don't know how old the child in question is. Any more suggestions anyone?

My daughter has a quarter size. She's four, and very average sized for her age, and it is the right size for her. But it does have a very irritating problem - it goes out of tune as you move up the fretboard. Very badly out of tune. Apparently this is common for the very little ones.

I've noticed that older children seem to trade up to a full size, once they get to about 11 / 12 years. I think this is probably related to the better tone quality you get with bigger guitars. There's a definite cost though - the instruments look clumsy in their hands and they struggle with bigger stretches.

Far be it from me to promote cheap and cheerful instruments
I have bought myself a 3/4 guitar from Argos for £19.99 for just such scenarios. I lowered the action and it wont ever be used for a concert, but it was worth the £20. When and if the time comes that it gets tired, it will be launched into the nearest skip with no great loss.
I can't really see the point of either myself or a parent buying anything more expensive, as kids grow out of stuff in no time.

Viohazard started at age 7 with about a 5/8th size guitar. It was a little big for him, but he had big hands and long fingers.

Too big: you could see that his arm was stuck out from his shoulder as he reached his right arm over the body to get to the strings.

Right size: his left hand was not straining to hold the thickness of the neck - his thumb and first finger were not forced apart, and he didn't have to strain to get his little finger to the right fret.

I think that's true enough.

By the time the child is really ready for a better guitar, they'll be ready for something full size. My daughter's 1/4 was £20 too.

Usually a 3/4 or 7/8 is the right size for child under 10 or 11 I am thinking of investing in one as kids uuall turn up with something that is so horrible it is not playable

Admira do some which are quite cheap and quite musical