Classical Guitar Sizes Explained: 4/4, 3/4, 1/2, 1/4

I’m Urs, writing from Berlin for the Federmeier blog. Sizing is the question I get asked most often for guitars bought as gifts — for a child, a grandchild, sometimes a partner who’s shorter than average. The instinct is almost always to size up “so they’ll grow into it.” I understand the logic. It’s also the single most common mistake in this whole category.

Why the wrong size actually slows down learning

A guitar that’s too big doesn’t just feel awkward — it changes posture. The left hand has to stretch further to reach the frets, the right arm sits at the wrong angle over the body, and a beginner ends up fighting the instrument instead of learning on it. Months of frustration, sometimes enough to make someone quit, usually trace back to a guitar sized for who they’ll be in two years rather than who they are now.

The size chart

Sizing is measured as a fraction of a full-size instrument, based mainly on scale length — the distance from the nut to the bridge, which determines both the guitar’s overall size and the string tension.

Size	Typical age	Typical height	Scale length
1/4	4–6 years	up to approx. 1.10 m	48–51 cm
1/2	5–8 years	approx. 1.15–1.30 m	52–56 cm
3/4	7–11 years	approx. 1.30–1.50 m	59.5–61.5 cm
4/4 (full size)	11 years and up, most adults	from approx. 1.50 m	63–65 cm

Treat the age column as a rough guide, not a rule. Two children of the same age can differ by a head’s height, and body proportion — especially arm length — matters more than the number on a birth certificate. If you’re buying for a child and can measure them against a guitar in a shop or a life-size printout of one, do that instead of guessing from age alone.

Adults aren’t automatically 4/4

This surprises people: a fair number of adults, particularly those under about 1.60 m or with smaller hands, play more comfortably on a 7/8 or even 3/4 guitar. There’s no rule that adult playing requires full size. Comfort at the fretboard translates directly into better technique, and better technique is what actually determines how quickly someone progresses — not the size stamped on the instrument.

One size doesn’t mean one guitar for years

Because a full-size guitar covers everyone from roughly age 11 through adulthood, a well-chosen 4/4 instrument is rarely something a young player outgrows the way they outgrow a bicycle. The sizes below that, though, genuinely are a phase — a 1/2 size guitar bought at six will likely need replacing by nine or ten. Buy accordingly: a solid but affordable instrument for the smaller sizes, and save the bigger investment for the size that will actually stick around.

If you’re still unsure

Send us the player’s height, and ideally their age if it’s a child, before ordering. It takes us two minutes to tell you which size fits, and it saves considerably more time than returning the wrong one.

— Urs