"Half, plus seven" is the age-old dating rule for dudes. It justifies the dating of younger women, within reason. The formula begins with each dude's age (for example, 22). That age is halved (22/2 =11), and 7 is tacked on to the divided result. Therefore, a 22 year old male may legitimately date an 18 year old female, a 25 male may date a female of 19.5, and a 30 male may date a female of 22. While there is no technical ceiling on this social anthropological formula, there is a point at which common sense takes over, and it just becomes disgusting. For instance, this formula should not be used to justify a 60 year old man dating a 37 year old female.
Half plus seven examples:

Guy's age: 20. Formula: (20/2)+7 = Minimum acceptable age of female: 17.

Guy's age: 25. Formula: (25/2)+7 = Minimum acceptable age of female: 19.5
by Jdim September 27, 2006
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1. You hear what Joe did? He choked his girlfriend with her own tampon! That kid is half-past seven!

2. You beat me, one-on-one? Shit, you must be half-past seven!
by Phroxen April 22, 2004
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Original definition: A man is most attracted PHYSICALLY to a woman half his age plus seven. (Rule of thumb).

Modern twist invented by frustrated younger guys: Minimum age that a woman must be for an older man to romance her.
He's infatuated with her , and she lacks any interest in him, so he cites this debunked "half plus seven rule" to justify his frustration with the guy that she's dating.
by Presence-Power July 4, 2016
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A rule the specifies the youngest person that a person of either sex can date without it being inappropriate. The rule is always calculated by the older person's age.
Kristi: I got asked out today by a guy who's 30.

Jason: Well, you are 22 so it fits the half-plus-seven rule...
by Dedao do pe September 23, 2009
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basically the idea that an age gap is fine, as long as the younger is half the olders age plus seven years.
"Dang doesn't she look a little young for Jim?"
"Well, ya know what they say, Half + Seven."
by JJisGae April 7, 2023
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