How to determine your own vocal type?

I am male, nearing my 17th birthday. I’m a member of YMT:UK, and I sing second tenor in choir. I’m very musical theatre orientated.

I’m talking tenor/baritone/bass please. I’ve heard that you may have a baritone range, and yet still be a tenor, and vice versa?

It’d really put my mind at rest, because it’s difficult to know what parts to go for etc.

I’ve been told both baritone and tenor by different teachers.