Age Rule 

The rule (invented by wise men but which should also be adopted by wise women) which states that half your age plus seven is the youngest acceptable age of a potential romantic partner. (Does not work inverted.)

Example: "C'mon, man, she's legal!"
"She's 19; you're 26. Just because she's not jailbait anymore doesn't mean you should date the girl. Don't you know the Age Rule?"
Number Example: 26/2=13. 13+7=20.

Age Rule by UnashamedBitch October 11, 2012

half-your-age-plus-seven rule 

A convenient rule to define the youngest that a romantic interest can be before the relationship is indecent. Widely referred to and used, the rule has merit for usefulness. The full version states: "if you halve your years then add seven, you'll have the youngest decent age for a partner; if you double your years then subtract seven, you'll have the oldest decent age for a partner".
However it's somewhat flawed thanks to the poor mathematical ability of its authors -- it gives a different result depending on whether it is worked out for a younger or older partner.

26-year-old Barbara waited patiently until Jack turned 20, fulfilling the half-your-age-plus-seven rule, before pursuing him romantically.

half-your-age-plus-seven rule by kriswa August 3, 2007

Half your age plus seven rule. 

A mathematical equation used to find the youngest age a person can date without being considered a disgusting, cradle robbing freak. (A/2)-7=Y, where A is your age and Y is the youngest you should date.

Conversely the rule can be inverted to find the oldest age a person should date. 2(A-7)=O, where A is your age and O is the oldest you should date.

John is 26 and dating a 20 year old named Kate, (26/2)+7=20. Their relationship satisfies the half your age plus 7 rule.

Kate is 20 and dating a 26 year old named John. 2(20-7)=26. This relationships satisfies the inverse of the half your age plus seven rule.

Half your age plus seven rule. by Trojan91 July 21, 2012