Now that Taylor Swift has a new boyfriend and is solidly dating model Joe Alwyn, we're all excited to see what hit song he'll eventually turn into. It's an old joke, yes, but here in the pop culture universe we get super invested in some celebrity relationships, and set our timers for others. Which makes us wonder? How long do Taylor Swift's boyfriends last?But more than that, how long does the relationship of any of Hollywood's other famous serial daters last?

MORE: The 9 Most Shocking Relationship Scandals

We did the math and estimated the average longevity of a celeb serial dater's relationship. Between adding and dividing the amount of time a star was with each of their confirmed — emphasis on "confirmed"— significant others, and examining their five most recent relationships, we were able to determine just how long these celebs' suitors typically last (i.e. not that long).

Scroll down and see for yourself!

Taylor Swift

taylor swift boyfriends

There was a yearlong hiatus when she substituted male arm candy with approximately 30,000 famous #girlsquad members, and then there was that yearlong span when she actually stuck with DJ/literal giant Calvin Harris. The latter definitely brought up the group average, and this new guy is treading steadily on the rough Swiftian seas.

But also maybe not. Either way, this is what we found.

The Average Taylor Swift Relationship Lasts: 4.4 months.

Leonardo DiCaprio

leonardo dicaprio girlfriends

God, you gotta love Leo for his diversity. Like seriously, whenever Victoria's Secret signs another tall, golden-haired model, is there just a clause in their contract that says they have to give Leonardo a go? Anyway.

The truth is that Leonardo's been around the block (understatement of the century). Though he's peppered his spare time with a series of forgettable flings, faceless girlfriends, and Rihanna, he's also had really long-lasting relationships. We forget that before Tom Brady snatched her up, he was engaged(!!!) to Gisele Bündchen for several years, and stayed with Bar Refaeli nearly as long.

So Technically the Average Leonardo DiCaprio Relationship Is: 2 years

Let it be known, if we were including every Leo hook-up from now until the end of time (the end of time being when he might stop his playboy ways) then we think his dating average would be down to milliseconds.

Ariana Grande

ariana grande boyfriends

Tbh, Ari is more about relationship-hopping in decently long spans versus dating in sprints. Everyone has a distinctive style, and her's seems to include suspiciously buoyant ponytails and having a serious boyfriend. What's really changed over the years is how she's gone from squeaky clean YouTube stars to rappers. They grow up so fast.

The Average Ariana Grande Relationship Is: 1 year and 2 months

John Mayer

john mayer girlfriends

Real Talk: the most traumatizing thing about researching this piece was realizing how dead-eyed John Mayer can look on the red carpet. WE KNOW, SOME GIRLS ARE INTO IT. Evidently, a lot of girls are into it, as dear John here has a long history of being a womanizer. Within that history includes a respectable relationship with post-divorce Jennifer Aniston, a dodgy relationship with post-divorce Jessica Simpson, and a three-ish year on-and-off thing with Katy Perry.

The Average John Mayer Relationship Is: A little over 10 months if you count his Katy Perry love drama as one solid block

Joe Jonas

joe jonas girlfriends

Purity rings be damned, this Jonas brother has definitely gotten around and put his Disney days faaaaar behind him. He has a lot of famous ladies in his past, but we like to know him as "the artist formerly known as the guy dating Gigi Hadid before Zayn Malik dated Gigi Hadid." Also this is legit the second ex-boyfriend of Taylor on this list. We are not throwing shade, that is just factual data.

The Average Joe Jonas Relationship Is: 8.5 months

Justin Bieber

justin bieber girlfriends

LOL.

But yeah, ok, this. There isn't much to say about The Biebs except that despite his torrid back-and-forth romance with Selena Gomez (who is now happily with The Weeknd, good for her) and some early teen romances, Justin Bieber is now all about having minute-long relationships with every model below the drinking age and a rumored three Kardashian-Jenners. We'd say that Leo would be proud, but uh, they're not really close.

The Average Justin Bieber Relationship Is: Tbh trying to count how many times Jelena broke up gave us an anxiety attack so we just gave up and went out for margs.