Have you ever wondered how long it would take for the entire world to become vampires?

Let say we started out with the set-up from your favourite vampire novel: Do Bram Stoker's *Dracula* vampires take over the world faster than vampires in *True Blood* or those in Anne Rice's *Vampire Chronicles*?

Dominik Czernia, a physicist at the Institute of Nuclear Physics in Kraków, Poland decided to find out, after seeing a paper by an international team of scientists investigating mathematical models of vampires and humans in fiction.

"It was quite a time-consuming project. I started by finding an interesting paper regarding vampires, where the authors subtly suggested the existence of vampires based on real-life data," Czernia told ScienceAlert.

"That drew my attention and I decided to test it out in a scientific way with the well-known theory predator-prey model, based on game theory. All of this was challenging and, because I focused on the calculator in my free time, it took me about a month to finish everything."

The result of all that painstaking work is a fun online calculator.

You can select which types of vampires you want to start out with, then change parameters such as human population size, the number of vampires, and whether there are any vampire slayers in the mix.

"I'm an absolute sucker (pun intended) for 'traditional' ruthless vampires, such as Dracula, but there have been so many interesting takes on vampires in literature and movies over the past years," says Czernia.

Now, we'll just warn you, in most of the models it is really hard to help the humans win. The vast majority of the time the vampires succeed in completely taking over.

But despite that, it's still fun to see how the numbers and graphs tell stories of a human-vampire war.

"I had to give meaning to raw numbers to build the atmosphere of a vampire apocalypse," Czernia adds.

"It combines two things that I find fascinating: fiction and science. I love it when we can apply mathematical models to even the most surprising things and describing a vampire apocalypse using differential equations definitely makes the top of my list."

And if a vampire armageddon ever does break out, well… now we can predict the outcome.

You can play with the Vampire Apocalypse Calculator at Omni Calculator here.