Home > Uncategorized > How Many Zombies Will There Be, Really?

How Many Zombies Will There Be, Really?

Zombie Walk in Edmonton

Zombie Walk in Edmonton (Photo credit: Wikipedia)

Here’s an interesting conversation we stumbled upon. “How Many Zombies Will There Be, Really?”

It draws some disappointing conclusions for zombie lovers.


Zombie Math
On Wed, Jul 14, 2010 at 4:21 PM, Deal wrote:
I took a few seconds to figure this out.
Let’s assume that we’re talking about zombies and not skeletons.
Meaning, not every dead body will zombify, only the ones that still have a
minimum level of tissue (rudimentary eyes, ears, brain function, movement
In a normal grave, 20 days after death the body has decomposed to the
point where bones are sticking through but most of the meat is still
around. Really, movie zombies are depicted as a LOT fresher than 20 days
old, more like 5 days old, but let’s play it safe and say 20 days.
There are 309,000,000 people living in the US. Every year, 9/1000 of
us die. That’s 2,781,000 deaths per year but only 152,383 in the past 20
days. Only 152,000 zombies! That’s just three Busch Stadiums worth, which
would be pretty scary but still totally manageable, and it’s spread across
the entire country. (I’m leaving the rest of the world out of it because
I’m assuming their zombies won’t really be able to wander all the way to the
US without incapacitating themselves or being incapacitated by their own
So, that leaves how many zombies per survivor? More accurately, how
many survivors per zombie? 2,027 survivors per zombie. That means that
when the inevitable happens we each only need to kill *one
two-thousandth* of a zombie. Or, if we assume that children and old
folks won’t do their share of the clean-up then we can round it up to one
one-thousandth of a zombie for every able-bodied woman and man. You, me,
and everyone else will get to kill 0.001% of a single zombie. That’s not
enough to go around!
But, you say, all of the zombies on outbreak day zero are going to
get the drop on us. Sure, let’s assume that every single zombie “recruits”
five humans in the first week (that seems pretty generous but okay). That
would inflate their numbers to 761,915 and cuts ours to 308,238,085. We’d
still outnumber them 400-to-1. Able bodied, 200-to-1. Two hundred kickass
people for every one putrefying jerk. What a letdown. How much does half a
percent of a single shotgun shell cost? Because that’s all you’ll need.
Please point out any errors in this analysis so that I can enjoy
movies and video games again.
– Deal

On Jul 14, 2010, at 3:39 PM, That Guy wrote:
You forgot to factor in the percentage of those bodies that are
cremated, and thus count against the principal numbers.

On Wed, Jul 14, 2010 at 3:45 PM, Kaiser wrote:
You also say that each zombie recruits 5 zombies in the first week
so you multiplied the zombies by 5. But each of those zombies would also be
infecting. The question is:what is the average number of people a zombie can
infect before it is permanently destroyed? If that number is 2 or more,
than we’re screwed.

On Jul 14, 2010, at 4:00 PM, Prescott wrote:
Absolutely, look at this formula and replace pennies with zombies.

On Wed, Jul 14, 2010 at 4:52 PM, That Guy wrote:
The rate of recruit will also be a degrading value. As we learn their
tricks and tactics, we will should be able to avoid them. This of course
assumes the zombie learning curve is zero. Also, as the percentage of
humans decreases, it becomes mathematically harder for them to recruit
more. The doubling penny theory is good, but remember those pennies are
coming from a limited supply in this case.

On Wed, Jul 14, 2010 at 4:10 PM, Kaiser wrote:
Maybe this would be useful?
So you’re saying that if each zombie can be guaranteed to infect 2
people before it’s destroyed, that rate can only be maintained until zombies
are 1/2 as populous as living humans, right?

On Wed, Jul 14, 2010 at 4:39 PM, Deal wrote:
Griff – “Simply put, not everyone is carrying a weapon on-hand, and
beserker zombies don’t feel pain and would be pretty resilient and hard to
battle in hand-to-hand combat.” You had me at simply put. =)
That Guy – you’re right, I didn’t count cremations.
Cremations currently occur in about 35% of burials, further dwindling the
ranks of the recently dead (and even more recently zombified) to around
50,000 nationwide. Assuming they each ambush five people* who each
ambush five people*, that still keeps us at (303,000,000 – 1,250,000) /
1,250,000 = 242 survivors for each zombie. Personally I believe we’re
being generous here in assuming that every zombie comprising the initial
wave will be responsible for 25 human victims in the first week, but even so
we’d still have a healthy advantage in numbers. If only 60% of us fight
then we have 144 survivors for each zombie.
I’m also assuming, as That Guy points out, that the kill rate will drop off
after the initial ambush because people will wise up quickly while the
zombie learning curve is zero. For this reason I tend to disagree with the
doubling pennies theory because zombies only have the advantage of
surprise. Once the survivors collect their wits (say, after the first week)
and get organized then their ability to kill multiple zombies will begin to
outpace the zombie ability to kill multiple humans.
– Deal

On Wed, Jul 14, 2010 at 4:45 PM, Martin Vega wrote:
That Guy and Kaiser are right that as the ratio of infected to healthy tips,
the spread will slow considerably. And to this end, Deal is right that
unlike a normal outbreak where people are unknowing carriers, people will
clearly be zombies and healthy people will quickly learn to avoid the
infected. I think that the graph would spike up quickly, plateau around the
40% zombie 60% healthy mark, and then eventually either rise to 100 or drop
to zero depending on the population’s response.

Kaiser wrote:

On Wed, Jul 14, 2010 at 5:08 PM, Kyo :
Two short points to build on…
First, Deal, you discounted the Eastern Hemisphere, which, I believe is
valid. However, you are forgetting the rest of North America in your
tally. In doing this, it would be especially useful to examine Mexico.
First of all, the infrastructure is crap and would not be able to mobilize
nearly as well as the United States. Also, I think we could all agree that
zombies would proliferate in the most crowded areas, correct? Mexico City
is second to only Bogota, Colombia in population density with 17,400,000
people crammed into 2,000 sqkm making 8,700 people per sqkm. I think we
could expect an sudden outbreak there to be devastating and nigh
uncontrollable. Where would said zombies come after they had their manwich
in Mexico? Following their food source, of course. Straight to the United
States, picking up the trail of the zombie refugees. Someone else will have
to do the math, but that’s a lot of zombies.
Second, Griff is spot on. If the Zombies are fast and berserking, I
believe 1 zombie is worth at least 10 people (knowing that 40% of that 10
would be worthless and freakin’ out). Putting that into the equation, you
can knock the 73 people down to 63 that would survive. On the other hand,
slow ass, weak zombies may be at a 4-1 ratio, thereby giving us a much
better chance at both success and hilarity… if you’ve seen zombieland you
know what I’m talking about.

On Jul 14, 2010, at 5:31 PM, Griff wrote:
Yeah central and south america wouldn’t have a chance. Our cities would be devistated, leaving only rural areas as potentail safezones.

On Wed, Jul 14, 2010 at 5:44 PM, Kazramierez wrote:
I think Griff has stepped on to something. The different relative densities of populations would play a major role in infection rates. Crowded cities like Chicago are screwed. So, when breakout occurs, and all you guys keep telling each other, “we have to get to Kaz, he’ll know what to do,” DO NOT! I’m already sucking on delicious brain soup. Never fall for that, “we hear there’s a safe area in Memphis bullshit.”. The damn second you hear of an outbreak anywhere hurry up and strand yourself on a desert (preferably dessert) island somewhere and shoot ANYBODY that shows up because all that’s going to happen is them secretly being infected.
Which brings me to my second point. If even one zombie is anywhere for any reason we are all fucked.

On Jul 14, 2010, at 5:59 PM, Kyo wrote:
Good job, Griff. You bastard. I guess the King of God gets all the credit.

From: Kaiser [mailto:]
Sent: Wednesday, July 14, 2010 8:49 PM
Subject: Re: How many zombies will there be, really?
T think the point taut deal was making eloquently and hansdomenly is that even if Teresa all a large amount of zombies right at the beginning, it’s way less than we’ve been let to believe

On Jul 15, 2010, at 7:55 AM, Griff wrote:
Keep in mind that while all of these are great points, all the Zombies are doing is taking our attention away from the fact that Skynet will have become self-aware and will eradicate all of us with Terminators. Leaving one to think that maybe it was Skynet all along that started the Zombie outbreak.
We are all screwed.

On Jul 15, 2010, at 10:20 AM, That Guy wrote:
I had the exact same question. Does the lifespan depend on the decay rate of a human brain? Will this rate continue to be constant, or will some kind of “sustenance” counteract the decay? Can the decay be counteracted as long as the zombie consumes more brains, or is there a maximum lifespan that a zombie will ever achieve?
Also, will the zombacalypse be limited to humans cadavers, or is there a chance I might get run down by a big gay zombie ape party?

On Thu, Jul 15, 2010 at 11:10 AM, Kaiser wrote:
Do these zombies have an expiration date? If I became a zombie and immediately fell into giant pit, would I die in 20 days when my body decayed? Or does someone that’s already a zombie continue to rot? Does a zombie starve to death without food? Crumble to dust after decades?

On Jul 15, 2010, at 11:02 AM, Kazramierez wrote:
A swarm of zombie ants is game over.

On Jul 15, 2010, at 10:25 AM, Kaiser wrote:
I think it has to be limited to humans. At LEAST mammals or else we have no chance.

On Thu, Jul 15, 2010 at 11:04 AM, Kaiser wrote:
What about zombie Protozoa? There’d be no reason to even bother resisting that.

On Jul 15, 2010, at 11:05 AM, Deal wrote:
I think the decay rate is roughly the same as a corpse. Eating brains or, to a lesser degree, eating any meat will stave off decomposition. If you fell in a pit then you’d decompose until you could no longer move muscles or anything. That would take 3-4 weeks, no more than like 6 weeks. I think you’d remain contagious, though, so if someone powdered your bones into someone else’s food then the victim would zombify anew.
– Deal


Like I said, a little sad, huh?

As always, if you’d like to get started with the Monster Exchange Program series, you can pick up issue 1, Blob Fits In, by clicking here!

  1. Nick
    March 25, 2012 at 8:31 AM

    How strong do we assume these zombies are?
    Have you seen coffins these days?
    They’re made out of various metal alloys and weigh hundreds of pounds. In addition, many coffins are sealed inside a concrete tomb to protect the coffin and the dead (for whatever reason). Could the zombies escape from that?
    A related thought: do we assume zombies get stronger once they’re awakened? If not, think of the state your body must be in in order to die. It has to be weakened on some level, if not simply aged past human life span. How does something so feeble escape from a 6foot deep concrete tomb?
    Doesn’t that take the numbers down ever further to the recently, unburied deceased?

    • terribogard
      March 25, 2012 at 6:09 PM

      I think we have to assume that the zombies can at least escape from their graves. The rotting hand bursting out of the ground is a pretty iconic zombie moment.

      I usually think that zombies are technically stronger than they were as living humans, but they have no strategy or idea about leverage or weak points. If a zombie grabs you, it’s game over. But even though they’re strong enough to break down doors, they tend to just shamble against them ineffectually.

  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: