Memory Sizes Explained – Gigabytes, Terabytes & Petabytes in Layman’s Terms

Ads by Google

memory sizes explainedIt’s easy to see that 500 gigabytes is more than 100 gigabytes. It’s also easy to see that 1 terabyte is larger than 1 gigabyte and that is larger than 1 megabyte. But these are all abstract terms and names. We can visualize 1 inch or 1 meter or 1 mile, but how can we visualize 1 gigabyte? 1 terabyte? 1 petabyte?

Our technology has progressed very far in the last decade or so, and with so much memory space available, it’s hard to really appreciate how much data capacity we have. Keep reading to find out just how big a gigabyte, a terabyte, and a petabyte are.

The Gigabyte = 1,024 Megabytes

memory sizes explained

We start with the lowly “byte”. In simplest terms, 1 byte is the amount of data needed to store 1 character (letter). If the average word is 6 characters long, then the average word is 6 bytes. For a 500-word essay, that’s 3,000 bytes.

You need 1,024 bytes to have 1 kilobyte (KB). You may recognize the “kilo” prefix from similar terms like “kilometer” and “kilogram”, both of which mean “a thousand meters” and “a thousand grams” respectively. But because of the way computers are designed, the number 1,024 is used in place of 1,000.

So a 500-word essay is 3,000 bytes, or 2.92 KB. A 200,000-word novel, then, would require 1,172 KB, or 1.14 megabytes (MB). The complete works of Shakespeare would take up approximately 5 MB of space in plain text format. 5 MB is also the average amount of space required for a 5-minute MP3 file.

Ads by Google

A gigabyte (GB) is 1,024 MB. That’s equivalent to 10 yards of books standing side by side. That’s 200 MP3 songs running at 5 minutes each. That’s a little bigger than the size of a feature film at standard definition. But most of us are already familiar with the term “gigabyte”. So what comes next?

The Terabyte = 1,024 Gigabytes

computer memory sizes explained

For a long time, hard drives were measured in GB. My 6-year-old laptop has an 80GB hard drive. My current desktop computer has a 300GB hard drive. But in the past few years, hardware developers have come out with 1- and 2-terabyte (TB) hard drives. How big of an improvement is this?

Well, 1 TB = 1,024 GB = 1,048,576 MB = 1,073,741,824 KB = 1,099,511,627,776 bytes. In other words, a 1 TB hard drive has the capacity to hold a trillion bytes. That’s a far step up from floppy disks that only held thousands of bytes.

Do you remember CD-ROMs? Way back before mp3 players and iPods and smartphones, music used to be sold and purchased on plastic laser-etched circles that would spin. These discs were large enough to hold 700 MB. How does that compare to the 1 TB hard drives of today?

You would need approximately 1,500 CD-ROMs to match the capacity of a 1 TB hard drive. Now, let’s say that the dimensions of a CD case are 142 mm x 125 mm x 8 mm (yes, I measured). If you stacked 1,500 CD cases on top of one another – and kept it from toppling over – it would reach a height of 12 meters, or 39 feet. You can enjoy all of that memory space within a compact metallic storage device now. Impressive.

The Petabyte = 1,024 Terabytes

memory sizes explained

And finally, we arrive at the newest data size that is slowly but surely becoming a norm in regular conversation – the petabyte (PB). The human brain reportedly has the ability to store about 2.5 petabytes of memories. The Large Hadron Collider generates around 15 petabytes of data every year. AT&T transfers approximately 20 petabytes of data through its network every day.

When we talk about data capacities in this range, it becomes hard to visualize just how grand of a scale we’re talking about. If 1 TB is a trillion bytes, then 1 PB is a quadrillion bytes. In scientific notation, that’s 1015! Even as I write this, I’m having a hard time comprehending just how big that is.

Our Milky Way Galaxy is home to approximately 2 hundred billion stars. If each individual star was a single byte, then we would need 5,000 Milky Way Galaxies to reach 1 PB of data.

Or how about television? If we were to count using standard definition TV episodes, then 1 PB would amount to around 10,000 hours of TV programming. If you watched all of those episodes without ever stopping – not even to eat, drink, or sleep – it would take you 2 non-stop years to watch it all.

This is the kind of capacity we have for data storage today. Quadrillions of bytes passing through our network cables right under our noses every second. Only 10 years ago, a single CD would hold maybe 20 MP3 songs; today, we can load up our HDDs and SSDs with thousands and thousands of songs easily.

Technology has advanced in great ways and data storage is no exception. I hope this article has given you a glimpse of just how far we’ve come.

Image Credit: Data Network Image Via Shutterstock, Infographic by Mozy.com

Join live MakeUseOf Groups on Grouvi App Join live Groups on Grouvi
Hacker Groups
Hacker Groups
101 Members
Technology Explained
Technology Explained
57 Members
Internet Crimes
Internet Crimes
43 Members
Internet Meme Origins
Internet Meme Origins
21 Members
Internet Piracy
Internet Piracy
21 Members
WWW Fact or Fiction
WWW Fact or Fiction
19 Members
Ads by Google
Comments (55)
  • Clare

    WOW! that is very amazing. I’ve heard of terabytes, but not petabytes! that is amazing to think of how vast our computer systems are, etc. This article is a massive help, thank you.

  • roy

    WOW MY TROUBLE NOW IS THAT MY BRAIN HAS JUST IMPLODED hehe…… but thankyou for imformation a big help ..

  • Faisal Ahmed

    “The human brain reportedly has the ability to store about 2.5 petabytes of memories.”
    I wish I could add some “RAM” on my memory!!!

  • Dos Moonen

    Please learn people the correct things. 1 KB = 10^3 bytes = 1000 bytes. Kilo stands for 1000. 1 KiB = 2^10 bytes = 1024 bytes. KB stands for KiliByte, KiB stands for KibiByte.

    This goes on for MegaByte (10^6 bytes), GigaByte (10^9 bytes), TeraByte (10^12 bytes) etc. and MebiByte (2^20 bytes), GibyByte (2^30 bytes), TebiByte (2^40 bytes).

    Thank you for feeding the confusion -.-

  • Evan Spangler

    This is neat, and really informative. It’s neat to see things like how much data Google goes through every day.

Load 10 more
Affiliate Disclamer

This review may contain affiliate links, which pays us a small compensation if you do decide to make a purchase based on our recommendation. Our judgement is in no way biased, and our recommendations are always based on the merits of the items.

For more details, please read our disclosure.
Affiliate Disclamer

This review may contain affiliate links, which pays us a small compensation if you do decide to make a purchase based on our recommendation. Our judgement is in no way biased, and our recommendations are always based on the merits of the items.

For more details, please read our disclosure.