The rule to define the youngest that a romantic interest can be before the relationship is indecent.
26-year-old Barbara waited patiently until Jack turned 20, fulfilling the half-your-age-plus-seven rule, before pursuing him romantically.
by Agnes "bob" Jedrzejewski November 2, 2005
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The social rule defining the youngest age one may date without it being socially unacceptable (or illegal). To compute the oldest one could date without it being socially awkward, simply subtract seven from one's own age, and multiply by two.

To compute the acceptable age an otherwise inappropriately matched couple would have to be before they could date, find the difference in their age, multiply by two, and add seven to get the age the older partner would have to be.

And remember, always round up when computing the youngest age you can date, and round down for the oldest. You know, just to be on the safe side.
Andy is 23, Betty is 19. Andy wants to know if they should date, so he computes half-your-age-plus-seven (18.5). This is an acceptable relationship.

Christine is 25, Donald is 43. Christine thinks she might be too young for Donald, so she reverses the half-your-age-plus-seven rule (36). This is an unacceptable relationship.

Eustace is 94, Frank is 46. Eustace considers the fact that half-your-age-plus-seven (54) makes this an inappropriate relationship to engage in. She also considers that she will be 110 before her relationship with Frank will be socially acceptable. She then considers the fact that she will be dead by then. Eustace continues on with her relationship with Frank anyway.
by Brash April 30, 2012
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The lower limit on the age of a potential partner for a person over 14, by socially acceptable standards. Used as a rule of thumb.

The converse is twice-(your-age-minus-seven).

The following online calculator makes the math easy and also calculates how long until an UNacceptable relationship becomes acceptable:

Dave: Yeh man, I totally banged that Kath chick last night.
John: Are you a pedo?! She's 15!
Dave: Nah, she's 15 and a half, half-your-age-plus-seven, I'm 17, so half my age is 8.5 and plus seven is 15.5.
John: ...Doesn't change the fact that she's my sister...
by SolF1729 June 19, 2011
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Other people are getting the reverse rule wrong. It would not be twice your age minus seven; it would be twice (your age minus seven).
- Dude, you're 40 and dating a 27-year-old. Isn't that a bit gross?

- Hey, half-your-age-plus-seven.

- Oh? So that means you would go for twice-your-age-minus-seven? So for you that would be 73.

- Actually, it's twice-the-quantity-your-age-minus-seven. So 66.

- ???

- I'm guessing you're too dense to see this algebraically. It's alright; we can take our results and work backwards. 73/2=36.5, and 36.5+7=43.5. However, 66/2=33, and 33+7=40. Got it?

- Ah, OK. So you'd go for a 66-year-old then?

- Fuck no.
by randomname25 February 27, 2010
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This is a very old rule of thumb: it is the calculation applied to a man's age that provides the age in a woman that he is most naturally attracted to physically. (Things change of course once you begin to actually TALK! :-o )

In recent years it has been misapplied to mean the lowest age that would be considered "decent" for him to date.

This new interpretation of the rule is actually quite bizarre when you consider the remarkable range of maturity among adults of both sexes at all ages.
That 50 year old think's he'll be able to romance that 32 year old. I'm not surprised he's attracted to her - she is the proverbial "half-your-age-plus-seven" - but let's see how far they really go together.
by Art M. September 11, 2009
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A clarification: the formula mentioned to determine WHEN an inappropriate relationship becomes appropriate is incorrect. The correct formula is to double the difference between the appropriate age of the younger person and the younger person's actual age. Conversely, this will equal the difference between the appropriate age of the older person and the older person's actual age. A SIMPLER FORMULA: The older person's age plus 14 minus twice the younger person.
Tim is 46; his girlfriend is 27. He shouldn't date under 30 according to the half-your-age-plus-seven rule; she shouldn't date anyone over 40. The relationship becomes appropriate in six years: 2 x (30-27) or 46-40, OR 46 + 14 - (2 x 27).
by TashTish December 27, 2014
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There's 1300 reviews on this phrase, and no one has managed to figure out the reverse of this rule? Surely my town wasn't the brightest of the lot?

If you're 40, 27 and younger is skezy, as 40/2+7 = 27.
If you're 40, 53 and older is skezy, as 40*3/2-7 = 53.
No one here seems to know how to write a formula. Half-your-age-plus-seven
by ep1032 October 16, 2010
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