Graph of the Half-age-plus-seven rule ("never date anyone under half your age plus 7"), which claims to dictate what age disparity between two people is acceptable in dating/romantic/intimate relationships during the late 20th century / early 21st century (called the "Standard creepiness rule" in the xkcd webcomic). According to this rule, the age of the younger person should not be less than half the age of the older person plus seven years, so that (for example) no one older than 65 should be in a relationship with anyone younger than 39 and a half, no one older than 22 should be in a relationship with anyone younger than 18, and no one under 14 years of age should be in a relationship at all...

From another point of view, the chart can be interpreted as saying that there should not be an age disparity of as much as five years unless the younger person has an age of 19 or more, a ten-year disparity should exist only if the younger person has an age of 24 or more, and a twenty-year disparity should occur only if the younger person has an age of 34 or more. (And people only slightly older than 14 should only be involved with those almost exactly the same age as themselves.)

To read the chart, go to the position along the x-axis which corresponds to your age, and the green range (between the black and red lines) directly above that position corresponds to the range of your partner's ages which is deemed acceptable by the rule. For convenience, the line representing x=y is also shown (in blue). The area between the blue and red lines shows where you are the older partner in the half-age-plus-seven calculation, while the area between the black and blue lines shows where you are the younger partner.