Drake Equation for Love Calculator

7.9 billion people in the world and you're single on Valentine's Day. What are the odds of that? Well, roughly 40% of the UK were partnerless in 2020, according to the latest data from the Office for National Statistics (ONS) and Scotland's 2011 census. It's safe to say your chances of being single are surprisingly high. But is there a scientific way to determine it? And can you increase your chances of finding love?

Peter Backus, an economist of the University of Warwick, set out to discover exactly that when he applied the famous Drake equation (for finding alien civilisations) to the dating world.

Our Drake equation for love calculator applies Backus's formula to tell you how many potential partners are out there and your chances of finding them — much like the Drake equation does, but for love instead of aliens!

Can you mix aliens, maths, and romance? Only one way to find out!

First, let's show you how to use our calculator and get your result. In the next section, we'll dig into the maths behind the calculator.

The calculator is really easy to use — just answer a few questions about yourself and your ideal partner, and it will work out how many matches are out there and your chances of finding them. Let's go through the calculator and get your results.

About you

• Location 🏙️ — Select the city where you live or one near you. This defines the pool of people the calculator will select from. If you are not near one of the listed cities, choose the "UK" option instead, or use the advanced mode (see below for details).

• Your attractiveness — Rate how attractive you are on a scale of 1 to 5 (5 being very attractive). It's best to be honest when answering this question. If you're unsure, ask a good and honest friend, or a stranger at the nearest coffee shop.

• Social skills — Say how well you get on with other people, on a scale of 1 (difficult) to 5 (very easy). Again, be honest and/or seek the opinion of those around you.

What are you looking for in a partner?

• Gender ♂♀ — Are you looking for a boyfriend or a girlfriend? You can also say you don't mind which gender.
• Minimum age — What is the minimum age of a partner that would be a good fit for you?
• Maximum age — What is the maximum age of a person you are looking for?
• University educated 🎓 — Should the person you're looking for have a degree or not? You can also say you don't mind either way.
• Attractiveness of people — Thinking about people that match your preferences so far, what proportion do you find attractive? Select one of the three existing options, or select "Custom value" to enter this factor as a percentage.

Results

Once you've entered all the inputs of the calculator, it will show you the number of potential partners that are out there. It also tells you the percentage chance of finding love based on the number of people in your chosen city or the whole of the UK. For a bit of fun, we compare your chances with the existence of an alien civilisation within 1000 light-years of Earth. 👽

Advanced mode

For those who want to specify your own factors to use in the Drake equation for love, click on the advanced mode button. Doing this displays the following inputs:

• Population of the UK — This is the base population figure that the calculator uses. You could change this value to reflect the population of a different country or region.
• Gender — The decimal fraction of the population who is the gender you are looking for.
• Location — The faction of the population of the correct gender who live near you.
• Age — The proportion of these people who are age-appropriate for you.
• University degree — The proportion of these people that have a university degree. If you don't mind about this option, enter 1.
• Single rate — The fraction of these people who are single and ready to mingle.

Once you have filled in all of these fields, the calculator will display the results using these inputs. Note that this result still takes into account your answers for your attractiveness, social skills, and your perceived attractiveness of people.

To switch back to basing the results on the standard mode of the calculator, remove one of the advanced inputs.

The original Drake equation (as formulated by the British astronomer Dr Frank Drake in 1961) uses Bayesian probability to calculate the number of alien civilisations in our galaxy with whom we could communicate. It famously states:

The result of this equation, $G$, is the number of contactable alien civilisations in our galaxy. The other values represent increasingly specific conditions (like $f_\ell$, the fraction of Earth-like planets that develop some form of life). This way, the number of alien civilisations that ought to exist is narrowed down.

Using his formula, Dr. Drake estimated that 10,000 alien civilisations may exist in our galaxy alone. While that sounds like an exciting number, there are more than 200 billion stars in our Milky Way. So, the odds of pointing your telescope at a random star and seeing E.T. wave back at you is around 0.000005%. And that's if Dr. Drake's parameter estimates were even correct.

Many years after Dr Drake's equation became famous, Peter Backus realised that a girlfriend might just be even more rare than an alien civilisation. Using the mathematical principles behind the Drake equation, Backus estimated the size of his dating pool and published his findings in a darkly humourous paper. His girlfriend-finding equation is:

Each variable whittles away at the population based on Backus's own criteria for a life partner — with the same maths as the Drake equation. The variables in the equation are:

By looking at data for the empirical parameters and estimating the rest, Backus found that 10,510 people meet his criteria. You might think it doesn't sound too bad — until he realised he didn't account for whether these people find him attractive, whether they are single, and whether they'd get along. After multiplying these extra fractions ($f_Q$, $f_S$, and $f_C$ respectively) at the end of his equation for love, the number of potential girlfriends dropped down to 26. In the whole of London. "Not great," as he had put it himself.

As he was so disheartened to find out, Backus's odds of finding a girlfriend were extremely low. And yet, a mere three years after publishing his paper, Backus got married to a friend of a friend he met at a dinner party. One of his 26 viable partners was only two degrees of separation away!

Girlfriends (unlike aliens) aren't science fiction. We don't know whether Backus's wife Rose matches all his criteria, but one thing is certain: if this pessimistic mathematician can find love against the odds he calculated himself, then so can you!

Love can be anywhere, and more people find it every day. There were more than 235,000 new marriages in the UK in 2018, and around 51% of the nation were in a marriage or civil partnership in 2020.

There are plenty of ways to beat the odds presented by the Drake equation for love, as Backus told TODAY himself.

In response to the bleak outlook of Backus's paper, love gurus and mathematicians alike shared their tips to find love:

• Relax your criteria. Based on her statistical studies, Dr Hanna Fry suggests that Backus underestimated many values in the equation when he reached his conclusion. She claims that if Backus was less picky (e.g., if he increased $f_B$ from his original 5% to 20%), he would increase his original estimate from 26 to 832.
• Dr Fry had also found that the happiest and longest lasting marriages are ones with "low negativity thresholds" — where conflict and anger subsides quickly. For this reason, the mathematician Bobby Seagull encourages stress-testing your potential partners and eliminate any that are easy to anger or argumentative. Perhaps bring up the latest about Boris?
• Put yourself out there. As Backus suggested, the more you expose yourself to the dating world, the greater your chances of meeting someone you can grow old with. It's just statistics — and common sense. And while Tinder has its hidden algorithms, there's no mathematical way to predict who you'll click with — you just have to take the plunge and go looking for someone yourself.