When to try one
If a larger guitar feels too long or wide, a half-size model may be comfortable. Seat the child and check whether they can reach the first frets without fully stretching the arm. Compare neck thickness and string height too.
Check actual dimensions
The half-size label does not mean every measurement is literally halved. Scale length, body and neck differ by maker. Try a three-quarter model as well before choosing.
Is a half-size guitar only for a certain age?
No. Fit and playability matter more than age or the number on the label.