Terabytes, Gigabyte and Petabyte – what do they mean?

Undoubtedly, one of the most common questions about technology that we are asked about these data storage metrics, such as terabytes, gigabytes, petabytes, megabytes, etc. You’ve probably heard of these terms before, but do you know what they mean?

How many gigabytes are there in a terabyte? What does a terabyte mean in the real world? These are all things you need to know before buying a hard drive or memory card, choosing a tablet-based on the memory it has, etc.

Fortunately, as confusing as it may seem at first glance, all these units of measurement are easily convertible from one another and are simple concepts to understand thanks to the examples we have provided below. Let’s start with the basics.

Read also: Megabit vs Megabyte- what is the difference?

Terabytes, Gigabyte and Petabyte- which one is bigger?

Immediately, knowing which one is bigger and which one is smaller, as well as the abbreviations that represent these numbers, is probably the most useful thing to start.

All these units of information storage technology are based on the byte, which is the amount of memory required to store a single text character:

• An exabyte (EB) is larger than a…
• petabyte (PB), which is larger than a…
• terabyte (TB), which is larger than a…
• gigabyte (GB), which is larger than a…
• megabyte (MB), which is larger than a…
• kilobyte (KB), which is larger than a…
• byte (B)

Less useful in the real world is a bit more small (there are 8 bits in 1 byte) and the largest zettabyte and Yottabyte, among others.

Byte is the unit normally used to describe the storage capacity, but there is also the bit that many Internet service providers (ISPs) use to describe the speed at which you can download data. It is important to understand the differences between bits and bytes to avoid confusion.

To convert from one unit to another, it is enough to know that for every level you climb, it multiplies by 1,024. Don’t worry if you feel confused- there are enough examples below, you will understand how to do the calculation in the blink of an eye. The table at the bottom of this article is also useful.

You will see many online sources saying that each new level is 1,000 times greater than the smallest, not 1,024. Although it is true in some cases, in practical terms, considering how computers use storage devices, 1,024 is the most realistic multiplier with which to perform the calculations. Now let’s move on to more practical things…

How many Gigabytes (GB) in a Terabyte (TB)?

There are 1,024 GB in 1 TB.

1 TB = 1.024 GB = 1.048.576 MB = 1.073.741.824 KB = 1.099.511.627.776 B

Let’s explain it in another way… A TB is 1,024 times bigger than a GB. To convert TB to GB, just take the TB number and multiply by 1,024 to get the number of GB. To convert GB to TB, just take the GB number and divide it by 1.024.

How many megabytes (MB) in a gigabyte (GB)?

There are 1,024 MB in 1 GB.

1 GB = 1.024 MB = 1.048.576 KB = 1.073.741.824 B

As in the previous example, a GB is 1,024 times larger than an MB. To convert GB to MB, take the GB number and multiply it by 1,024 to get the MB number. To convert MB to GB, take the MB number and divide it by 1.024. Megabytes and megabits are different units of measurement.

How big is a terabyte?

The terabyte (TB) is the most common unit used to measure the size of the hard drive and a number that you might actually encounter from time to time.

A single TB is a lot of space. It will take 728,177 floppy disks or 1,498 CD-ROM disks to store only 1 TB of information.

• As of 2018, most of the new computer hard drives at a modest cost are between 1 and 3 TB.
• Many ISPs limit monthly data usage to 1 TB.
• The Hubble Space Telescope generates about 10 TB of new data every year.
• About 130,000 digital photos would require 1 TB of space… almost 400 photos every day for a year!
• IBM’s famous Watson gaming supercomputer has 16 TB of RAM.

As you saw earlier in mathematics from GB to TB, 1 TB equals a little over a trillion bytes.

How big is a petabyte?

Storing a single PB would require over 745 million floppy disks or 1.5 million CD-ROMs, clearly not an effective way to collect a petabyte of information, but it’s fun to think about it!

• The movie Avatar needed about 1 PB of memory to display that graphic.
• It is estimated that the human brain can store about 2.5 PB of memory data.
• Over 3.4 years of Full HD 24/7 video recording would have a size of about 1 PB.
• At the end of 2016, the Wayback Machine was storing 15 PB of data!
• 1 PB equals over 4,000 digital photos a day, for life.

A single PB is 1,024 TB… this number was already big on its own! In an even more impressive view, 1 PB equals over 1 quadrillion bytes!

How big is an Exabyte?

Even talking about a single EB seems a bit crazy but there are situations where the world really comes across this level of data.

Yes, it is comical, but going back to the previous comparisons- to reach a single EB it would take 763 billion floppy disks or 1.5 billion CD-ROMs. Can you imagine it?

Some amazing examples:

• Back in 2010, the Internet already managed 21 EBs a month and almost 6 times this number only seven years later.
• Nearly 11 million film in 4K format would fit comfortably inside a storage device 1 EB.
• A single EB could contain the entire Library of Congress 3000 times.
• A single gram of DNA can contain 490 EB, at least in theory. There are over 5 billion films in 4K.

Now for mathematics- a single EB is 1,024 PB or 1,048,576 TB. It’s over 1 quintillion bytes! Does this number actually exist in practice?

How big is a gigabyte?

Speaking of GB is a little more normal- we see GB everywhere, from memory cards to movie downloads, to smartphone data plans and more.

A single GB equals little more than 700 floppy disks or a little more than a single CD.. little for the numbers we talked about above.

A GB is not a small number at all, but nowadays it is a level of data that we use quickly, sometimes several times a day. It is a number that we always come across.

• 1 GB can store almost 300 songs in an MP3 format.
• A single Netflix movie in HD could be over 4 GB. A 4K version could have a capacity of over 20 GB!
• A disc with a DVD movie contains about 9.4 GB.
• Most smartphones store 64 GB or 128 GB of data ( apps, music downloads, etc.).
• The data plan of your smartphone, which you use when you’re away from the wireless network at home, could be limited to 5 GB, 10 GB or a little more per month, Iliad 50GB to € 8 a month.

As we have shown in the conversion from MB to GB previously, 1 GB equals over a billion bytes. It is not a small number, but it is no longer an impressive amount as it used to be.

The byte table

Here it is all together, which helps to illustrate how big some of those big numbers become!