Formula for dating age difference Sexchatnocredit
This trope is when a specific formula or calculation is proposed to determine either the "ideal" age gap, or the maximum allowable age gap before it becomes "creepy".
(One common criterion for compatibility between prospective marriage or romantic partners is the difference between their ages.
So the ripe old age of 14 -- the age when you still have pimples, are as insecure as can be and are unlikely to get anything more than a kiss from a woman your own age -- is the only time when you can enjoy dating a woman your own age? Add seven to that, so you can date a 12-year-old -- an older woman"?
What about if your 10-year-old looks at you and says, "I'm ready to date, Dad"? There is so much a 12-year-old can teach a 10-year-old -- advanced coloring, advanced texting, and so many other important life skills. You're 20 years old and, under this rule, you can date a 17-year-old. There you are in college, and you get to go back to high school again to find a girlfriend.
I contend that as long as nobody is being willfully creepy (I see you, guys in Ferrari hats), this kind of limitation is mega lame.
As Society Marched On, this became less and less the case, and in modern works a very small age gap is often considered ideal, with a maximum allowable (as opposed to "ideal") age gap proposed, and often applied equally in either direction (older man vs. One commonly-applied formula is the "half your age plus seven" rule, in which the older partner's age is divided by two and then increased by seven to reach either the ideal or minimum allowable age for a romantic partner.
Traditionally, a man was expected to be established in his career and lifestyle before marriage, whereas a woman usually transferred directly from her father's household to her husband's within a couple years of reaching adulthood, so it was considered ideal for the man to be at least somewhat older.
The rule would theoretically create a paradox for people under 14, because the younger partner would have to be older than the older partner, but 14 is about the youngest you can be and make anything even remotely resembling adultish decisions respecting relationships anyway, so this rule works out rather well.
This has the advantage of allowing for a larger age gap the older the partners get; the four-year age gap between a 22-year-old and an 18-year-old is significant (and just barely allowed by this rule), but the same age gap between an 86-year-old and a 90-year-old isn't worth comment.
A convenient rule to define the youngest that a romantic interest can be before the relationship is indecent.