It’s so dependent on the people in the relationship, imo. In general for this particular stage of my life, I think 5 years older is probably the cut-off for being in the same maturity range as me, but if I met someone say 10 years older & we happen to be a good fit for each other, I wouldn’t turn them down just because of their age. Right now, I can’t see being in a relationship with someone 20 years older being a fantastic idea because we’d more than likely be in such different stages in life and have such different mentalities, but you never know, I guess Maybe my soul-mate is already in their 40s So generally speaking, for this period of my life, 5 years is my “limit”, but I also don’t really have a limit if it seems like it’d be a good idea to enter into a relationship with each other. For where I am in life right now (almost 21), I can’t see myself with someone younger, but I’m sure I’d feel differently if I were older. [name_f]My[/name_f] great aunt is 15 years older than her husband & they’ve been happily married for 37 years.
ETA: I feel like age is a general guide for where someone is in life, but can vary so much from person to person, so there’s no real answer to your question from me.