How Long Will Your Relationship Last? This Handy Mathematical Equation May Tell You

It’s pretty universally accepted that the language of nature is mathematics — but can math really predict how long your relationship will last? According to the folks at MSN, maybe.

I’m not totally sure I’m sold on it, but for the curious, MSN put together an equation based on their research that can allegedly tell you whether or not the relationship you’re currently in is long-term material. Says MSN’s relationship expert and psychologist, Corinne Sweet, “The MSN Spring love formula can help determine the traits we should be looking for. It can even indicate how long a relationship might last, based on compatibility and mutual goals. Forewarned is forearmed, even in love.”

Here’s the equation for heterosexual couples:

L = 8 + .5Y – .2P + .9Hm + .3Mf + J – .3G – .5(Sm – Sf)2 + I + 1.5C

If you’re anything like me, it looks like something that might resemble algebra, but which is actually gobbledygook. It starts to make a little more sense when you know what all the letters represent, though, so here’s the breakdown of those for you:

  • L: The predicted length in years of the relationship
  • Y: The number of years the two people knew each other before the relationship became serious
  • P: The number of previous partners of both people added together
  • Hm: The importance the male partner attaches to honesty in the relationship
  • Mf : The importance the female attaches to money in the relationship
  • J: The importance both attach to humor (added together)
  • G: The importance both attach to good looks (added together)
  • Sm and Sf: The importance male and female attach to sex
  • I: The importance attached to having good in-laws
  • C: The importance attached to children in the relationship

Anything that measures the “importance” of something can be rated on a scale of one to five, with one being not important and five being very important. Interestingly, the magic value of P — that is, the value that leads to the sturdiest results — is 10, or five previous partners for each person. Iiiiinteresting. Oh, and yes, the equation does change a little for same-sex couples:

L = 8 + .5Y – .2P + 2J – .3G – .5(S1 – S2)2 – I + 1.5C

You’ll notice that Hm and Mf are gone, and that SM and SF have become S1 and S2.

Alas, I am unable to test the formula myself at the moment; my SO works one of those crazy jobs where occasionally he’s on the night shift, so he’s fast asleep at present. However, a reporter at the Telegraph did get a chance to test it out — by broadcasting via Twitter that she was “single and ready to mingle in a mathematically approved fashion.” After applying the formula to a wide number of applicants, she found one with whom she would apparently be able to carry on a 12.9-year love affair. The only problem? She wasn’t at all attracted to him, and neither was he to her. Ah well. Apparently math can only go so far when it comes to explaining complex phenomena like L-O-V-E. Maybe neither of them were on lucky number five!