The Mathematical Equation For Love That *Wasn’t* Taught in School
I failed finite math in college… 4 times. I finally passed on my fifth try during my fall semester of senior year. I ended up taking the class at a local community college that allowed me to use a calculator during tests, mind you, this class required students to then take statistics (which I killed btw) in order to graduate. What did I learn from this, 4 years post-grad? Well, a) some math skills could have helped save me a bunch of student loans payments and b) that I could use math to calculate things I actually care about: relationships, sex, and Swedish Fish. Now, I know that math comes into play when I’m standing in line at 7/11 calculating the sales tax on my gummy snacks (because yes, I might be the last person on earth who pays in cash), BUT I had no idea until reading When Should We Settle Down? by Hannah Fry that my least favorite, money stealing, no calculator having, a bullshit subject called math could actually help me find, dare I say it, the one.

“The one” is a loaded term, but for simplicity’s sake, just think every Disney movie’s happy ending. The one and only other human you’re “supposed” to be with. We can’t tell you exactly when it happens, but there comes a time in our lives where we develop a longing for domesticity. We want someone to watch Netflix with, to lounge around on sleepy Sundays with, to be our automatic wedding date, and to get into that perfect, comfortable sexual routine with. Please, take this with a grain of salt as we know that it only applies to a fraction of individuals. This being said, the apparent “need” to settle down creeps up and kicks us in the ass without warning. However, just because you might be ready to settle down doesn’t mean you can be certain the time is right.
As Hannah puts it through the lens of her mathematical mindset, there’s “fine balance between having the patience to wait for the right person and the foresight to cash in before all the good ones are taken. Once you decide to settle down and take yourself out of the dating game, you can’t look ahead to see all the partners you could have had on your list, but equally, once you reject someone, you can’t go back and change your mind at a later date.”
This is where *ugh/yay* math comes in. Did you know that there’s a mathematical equation that can help you discover the proper time to settle down? Who knew, that math could actually translate into the language of love. There’s a theory of optimal stopping where a problem presents itself, the problem of choosing a time to take a particular action, in order to maximise an expected reward or minimise an expected cost.
This actual equation “can offer the best possible strategy in your hunt for ‘The One.’ and the conclusion is surprisingly sensible: spend a bit of time playing the field when you’re young, rejecting everyone you meet as serious life-partner material until you’ve got a feel for the marketplace. Then, once that phase has passed, pick the next person who comes along who’s better than everyone you’ve met before.
But optimal stopping theory goes further; it turns out your probability of stopping and settling down with the best person (denoted by P in the equation below) is linked to how many of your potential lovers (n) you reject (r), by a rather elegant formula:”

How many people should you reject to give you the best possible chance of finding your perfect partner? Hannah goes on to tell us:
- If you are destined to date ten people in your lifetime, you have the highest probability of finding ‘The One’ when you reject your first four lovers (where you’d find them 39.87 percent of the time).
- If you are destined to date 20 people, you should reject the first eight (you’d find them at 38.42 percent of the time).
- And, if you are destined to date an infinite number of partners, you should reject the first 37 percent, giving you just over a one in three chance of success
- If you chose not to follow this strategy and instead opted to settle down with a partner at random, you’d only have a 1/n chance of finding your true love, or just 5 percent if you are fated to date 20 people in your lifetime, for example. But by rejecting the first 37 percent of your lovers and following this strategy, you can dramatically change your fortunes, to a whopping 38.42 percent for a destiny with 20 potential lovers.
Say you start dating when you are 15 years old and would ideally like to settle down by the time you’re 40. In the first 37 percent of your dating window (until just after your 24th birthday), you should reject everyone — use this time to get a feel for the market and a realistic expectation of what you can expect in a life partner. Once the rejection phase has passed, pick the next person who comes along who is better than everyone who you have met before. Following this strategy will definitely give you the best possible chance of finding the number one partner on your imaginary list. But, a warning: Even this version has its flaws.
… wanna read more of her amazing work? Check out the full book here!
Or watch the full video here:
As human beings, we analyze and re-analyze all of the goings on in our lives. We calculate possible outcomes for our actions, and we re-live our experiences over and over again to try and understand them to the fullest. For many individuals, life is a careful equation, but for some reason, these calculations do not translate over into our romantic actions. Often we blindly follow our hearts and associate no practical, analytical data to our loves lives. Well, wouldn’t you say that adding a little math into the mix might be a good idea? If we see love as a set of stats and equations like we see everything else, we may be able to gain a little perspective and remove ourselves and our hearts from the narratives from time to time. This is not to say that we should follow only our heads rather than our hearts, but it is to say that “everything happens for a reason” may fall a little short when it comes to explaining the happenings in our lives.
It’s all about math, people. There’s no escaping it. Also, how cool is Hannah Fry!?
Excerpted with permission from the book The Mathematics of Love: Patterns, Proofs, and the Search for the Ultimate Equation, by Hannah Fry, published by TED Books/Simon & Schuster. © 2015 Dr. Hannah Fry.