Most untrained beginning singers have a PRACTICAL range of between an octave and a few notes, to an octave and a fifth.
25+ years ago, for example, when I took a college singing course my practical range was about an octave and a half.
About 9 years later when studying with a (great) vocal teacher, it expanded to around an octave and seven notes when singing on my own. With the instructor supervising me directly, it was two octaves and one note. We determined it was more than adequate
in range, tone quality, size, to pursue the option of an operatic career. (choose not to)
Nowadays it's about two octaves and two notes if I'm in good voice, warmed up, etc., although the lowest note is greatly enhanced by using a microphone vs. a capella.
For men, it's rare to have someone who can sing much beyond this. Women easily can go 2 1/2+ octaves plus, especially sopranos.
The most important factors usually are tone quality, and singing the proper type of material for a given vocal classification-
tenor, baritone, bass, alto, soprano, etc.
Just keep singing without any straining!
Chris
P.S. The singing ranges above do NOT count falsetto BTW.