Age range for dating calculation
Martin, then, shouldn’t date anyone younger than 26 and a half; Lawrence shouldn’t go above 34.
The rule is widely cited, but its origins are hard to pin down.
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.
In its first known appearances (in the book Her Royal Highness Woman by Max O'Rell, "The little shepherd of Kingdom Come" by John Fox, and the 1951 play The Moon is Blue by F.
Hugh Herbert), it's stated or implied that at the beginning of a relationship or marriage, the woman's age "is supposed to be half the man's age, plus seven", which gives a different (asymmetrical) interpretation to the rule.
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.
1880, he thought that the ideal ages for husband and wife at marriage would be if the woman's age was half the husband's age plus 10. Self-made graphic, with layout partially influenced by the PD image en:image: Half Plus Seven Graph 2.