There’s the half your age plus 7 rule, but it doesn’t really work if you are under 22.
Doesn't it?
- 14/2+7 = 14. It's questionable for anybody under 14 to be in a romantic or sexual relationship even if the other person is the exact same age.
- 16/2+7 = 15. People tend to mature rapidly in this age range, so dating someone much younger is sketchy.
- 18/2+7 = 16.
- 20/2+7 = 17.
These line up with my intuition for the age gap being acceptable, not something that should raise eyebrows. A little outside that becomes a warning sign. A lot outside that is almost certainly abusive.