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I found this first on a funny post online and discredited it as just a fun fact, but I have been reading it on comments online and people tweeting about it.

Can the human brain store 4TB of data? How is that measured? Are there any studies to support that claim?

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I'm not even sure you could calcuate this without defining an encoding scheme first. – rjzii Sep 27 '12 at 11:52
4TB is nothing! I could back myself up just using the old spare hard drives sitting around my house. – matt_black Sep 27 '12 at 11:55
Agree on both of the comments, how can we discredit this then? Anyone knows about any comparisons or studies done one this? – Bruno Pereira Sep 27 '12 at 15:35
important reference: ;-) – vartec Oct 2 '12 at 16:11
Considering how little we know about human memory, it is pretty hard to provide any sort of realistic estimate. If memory is holonomic, for instance, the estimates for capacity are orders of magnitude higher. – James Christopher Oct 10 '13 at 23:04
up vote 18 down vote accepted

The human brain consists of about one billion neurons. Each neuron forms about 1,000 connections to other neurons, amounting to more than a trillion connections. If each neuron could only help store a single memory, running out of space would be a problem. You might have only a few gigabytes of storage space, similar to the space in an iPod or a USB flash drive. Yet neurons combine so that each one helps with many memories at a time, exponentially increasing the brain’s memory storage capacity to something closer to around 2.5 petabytes (or a million gigabytes). For comparison, if your brain worked like a digital video recorder in a television, 2.5 petabytes would be enough to hold three million hours of TV shows. You would have to leave the TV running continuously for more than 300 years to use up all that storage.


I'm no medical expert by any means, but according to this, roughly 2.5 petabytes. This seemed a little high so i looked some more.

The brain has about 100 billion nerve cells, so at least that many bits (about 10 gigabytes) could be stored, assuming the brain uses binary logic. But it probably doesn't do so. Instead, information is believed to be stored in the many connections that form between the cells. This is a much larger number: Current estimates of brain capacity range from 1 to 1000 terabytes! It would take 1,000 to 10,000 typical disk drives to store that much information.


This second article explains that if the brain used binary storage then it would be 1-10 terabytes, most likely around 3. But since the brain does not and it stores information in the connections it is much likely a lot more. But this article was written in 2000 I think.

The first article is on the high side, while the second article is on the more realistic side. But the truth is that no one knows because with the technology that we have and understanding of the brain it is impossible to accurately calculate this. from other sources that I have read it looks like between 3-100 terabytes is what is generally accepted. This is a large range, but because we don't know exactly. And a lot of the calculations assume things that we, as of right now, cannot be 100% certain on. was another good article.

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My wife would figure out how to get 300 years worth of real house wives and I would never be able to see my shows anyway. – Chad Sep 27 '12 at 16:50
Watched an interesting video the other which may be of interest. It is estimated that we can store the entire worlds knowledge in a mere 4 grams of DNA. – Magrangs Sep 28 '12 at 9:21
I had read an article about this as well. 5.5 petabytes of data per gram of DNA – Cruril Sep 28 '12 at 15:46

Considering the estimated number of neurons differs by factors of ten depending on who you read, this can't be answered. The brain does not work like a computer (whether that is good or bad, I am not sure)

Also, the human brain does not use 10% of its capacity.

neuron counts.

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Also, the human brain does not use 10% of its capacity. would need to be cited if it were relevant. It is not so should probably just be removed. – Chad Sep 27 '12 at 16:52
Even with your sources for the neutron counts the first sentence is a non sequitur. As you can see in the first answer, the factor 10 difference in estimate makes no difference on the answerability of this question. – Konrad Rudolph Sep 28 '12 at 17:43

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