One of the first and most important aspects you should consider when purchasing any computer device is its storage. Whether it is a phone, laptop, or any other device used to surf the web, its volatile and non-volatile storage plays an essential role in determining its efficiency.
Volatile storage, i.e. RAM, is used by the operating system. It stores data temporarily as it loses the content when the hardware is switched off. On the other hand, non-volatile storage (ROM) is erasable, programmable, and retains data even when the device is shut down.
All in all, memory types come in different capacities that determine how much data they hold. You may have heard of MB, KB, or GB storage, but you need to know what they entail.
Don’t worry, the rest of this article will give you insight into the different file sizes while providing a comparison to give you a better understanding. You don’t have to buy your devices blindly anymore. Let’s get to it!
What Is File Size?
Like all quantifiable measurements, device storage is classified into various units according to the file size it can hold. In most cases, you may have heard people measure storage space primarily in megabytes (MB) and gigabytes (GB). However, the scope is greater than that.
In layman’s terms, file size refers to the data a device contains. Different devices have different storage capacities, and every file takes up a certain amount of space. So, the more storage space, the more files you can store on your device. Additionally, larger file sizes take more time to download.
File size units measure a device’s RAM and ROM; however, they are distinct. While the former is the computer’s temporary CPU memory, the latter is the space available for the device to store files and data you need. The common units of measuring data storage include:
- Bite,
- Kilobyte,
- Megabyte,
- Gigabyte,
- Terabyte,
- Petabyte,
- Exabyte,
- Zettabyte,
- Yottabyte.
Byte
The first file size explained is the byte, a term developed in 1956 by Werner Buchholz to represent the smallest unit of data in a computer system. It consists of either seven or eight bits, depending on whether or not it contains an error. The binary digits (bits) have information registered in the computer in values of either 0 or 1, which bind together to form a byte. For instance, a single byte is written as either (00000000) or (11111111).
To give a visual outlook, a single byte is usually represented on computers by either numbers, symbols, or characters. So, the letter ‘s’ is one byte made up of a string of eight bits, while the word ‘soup’ consists of four bytes. The unit is abbreviated by the letter ‘B’ when discussing file sizes or device storage.

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People rarely look at file sizes in terms of bytes in the modern world, as it is more practical to use kilobytes and megabytes. Nonetheless, it is undisputedly the smallest unit of measurement in any operating system. A culmination of 1024 bytes makes up one kilobyte, but since most files are more extensive than 1024 bytes, they are usually quantified in kilobytes.
Interestingly, it is common for people to assume that 1000 bytes equate to 1 kilobyte. This is an understandable mistake since it is odd to refer to a kilobyte as 1,024 bytes. So, it is easier to ignore the additional 24 bytes. However, the 24 bytes get more significant with increasing file sizes.
The National Institute of Standards and Time (NIST) and the International Electrotechnical Commission (IEC) tried to fix this issue by introducing another unit of measurement, kibibyte. The proposed unit was to represent 1024 bytes while a kilobyte would remain as 1000 bytes. However, these efforts were unsuccessful as there needed to be more sensitization. People are also already used to kilobytes.
Kilobyte
The next measurement standard for file sizes is a kilobyte, which is larger than a byte and smaller than a megabyte. The unit is abbreviated as ‘KB’, but ‘K’ also works in informal conversations.
According to the International System of Units (ISU), one kilobyte is equivalent to 1000 bytes, primarily because the ‘kilo’ prefix is associated with 1000 (10³). Thus, it makes sense that 1000 bytes should equate to 1 kilobyte, just as the same number of grams equals one kilogram.
The IEC recommended this definition, and it is primarily used with data transfer rates between computer networks, media transfer speeds, and storage media such as flash drives, DVDs, and hard disks. However, initially, and in formal settings, 1 kilobyte equates to 1024 bytes, following the powers of two (2¹⁰ B) metrics. Most operating systems and RAM capacities use these metrics due to the binary composition of file sizes.
While kilobytes were considered relatively large file sizes in the past, they are currently almost obsolete. With file capacities running in gigabytes, kilobytes are connected with small files such as text documents and some low-quality images.
Megabyte
The next file size explained is the megabyte, which is larger than a kilobyte and smaller than a gigabyte. It is a standard unit of file size and storage presented as MB in micro SD cards and other devices. If you have downloaded anything on the internet or handled computer files, you have seen the abbreviation. But what does it represent, exactly?
According to the ISU, a megabyte equals 1000 kilobytes and 1 million bytes. This is per the body’s ‘power of 10’ system, which links the ‘mega’ prefix to a 10⁶ multiplier. However, when it comes to disc space and file storage, most people in the computing profession stick to contemporary binary units.

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Therefore, according to their metrics, a megabyte comprises 1,048,576, which is 2²⁰ bytes. Big players in the tech industry, such as Microsoft, stick to this metric when developing their computer RAMs and accompanying storage.
Since a megabyte is relatively large, it is used to measure file capacities of storage devices such as Compact Discs which, nowadays, carry approximately 600-700 MB. Other small files, such as music and short videos, also fall into the file size’s scope.
Gigabyte
The next file size explained is the Gigabyte, abbreviated as GB; it is arguably the most commonly used file size in the modern world. Most games, applications, and storage devices fall within this file size. The smartphone you use probably has between 32 and 256 GB of storage.
The Gigabyte is more significant than a Megabyte and is the file size that precedes a terabyte. From the prefix ‘giga,’ the file size is described as 10⁹ by the International System of Units, equating to 1 billion bytes.
This decimal system also sets the standard measurement equal to 1,000 megabytes and 1 million kilobytes. Nonetheless, the ever-conflicting binary systems state that a gigabyte is equivalent to 1,024 megabytes. This translates to 1,048,576 kilobytes and 1,073,741,824 bytes, in line with the power of the two calculations the system prescribes.
Terabyte
If you handle loads of data or own a powerful laptop, you may have come across, or at least heard of, a terabyte. The storage and file size unit is larger than a gigabyte, equating to 1,000 GB. It is abbreviated as TB, which is quite a coincidence as it roughly translates to 1 trillion bytes.
However, the binary system, considered more accurate in storage systems, correlates 1 Terabyte to 1024 GB, 1,048,576 MB, 1,073,741,824 KB, and 1,099,511,627,776 B. This comparison reveals how huge a terabyte is in file size and storage. It is almost impossible for the average person to exhaust the storage.
To put matters into perspective, a 1TB file, culminated data, can fit in about 720,000 floppy disks and 1,400 Compact Disks. It is a wonder that most modern computers and hard drives can store such quantities of information.
Petabyte
It is hard to imagine a larger file and storage size than the Terabyte. The Petabyte, abbreviated as PB, is a crazy amount of data that equals 1024 or 1000 TB, depending on your preferred system (ISU or IEC). In terms of bytes, the Petabyte is 10⁵ B in the decimal system and 2⁵⁰ in the binary system.
It is impossible to fit this file or storage in a single device. Instead, it is used to quantify data stored in large computer networks and servers. Interestingly, a petabyte is as large as the memory of a human brain, which can store up to 2.5 PB of information.
Exabyte
An exabyte is larger than a Petabyte but smaller than a Zettabyte. It is an impressively huge data storage and file size abbreviated as EB. Like all file and storage sizes, a single Exabyte comprises bytes, its primary storage units. The ISU system denotes that 1EB contains 10¹⁸B.

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Nonetheless, the more accurate binary system states that it contains 1024PB, which is 2⁶⁰ Bytes. This is a substantive amount of storage that can hold the whole catalog of music ever produced. For perspective, you can play music from exabyte storage for several hundred thousand years without exhausting the songs.
So, where exactly are exabytes used? Just like the Petabyte, it is impossible to contain the Exabyte capacity in one device. Thus, it is used to quantify the amount of data transferred across multiple systems.
Zettabyte
Abbreviated as ZB, a zettabyte is one of the most developed storage and file capacities. According to the ISU system, the decimal prefix, Zetta, denotes that the storage capacity equates to 10²¹ bytes. On the other hand, the binary system that computers use for their calculation denotes that 1ZB corresponds to 2⁷⁰ bytes. This storage capacity is so large that the whole world’s data makes up only a few zettabytes.
Yottabyte
The last file size explained is the Yottabyte, the largest storage measurement unit. It is an almost impractical storage and file size as it contains about 10²⁴ bytes or 2⁸⁰ bytes on the binary system. This equates to around 1 trillion Terabytes. It is impossible to use this unit of measurement since all the world’s data is just a few Zettabytes. A Yottabyte is so large that the naked brain cannot comprehend it.
Comparison of Different File Sizes
File | Size in Bytes |
---|---|
Byte | 1 |
Kilobyte | 1024 |
Megabyte | 1,048,576 |
Gigabyte | 1,073,741,824 |
Terrabyte | 1,099,511,627,776 |
Petabyte | 1,125,899,906,842,624 |
Exabyte | 1,152,921,504,606,846,976 |
Zettabyte | 1,180,591,620,717,411,303,424 |
Yottabyte | 1,208,925,819,614,629,174,706,176 |
Conclusion
It remains astonishing that floppy disks were still relevant up to 2010 but are virtually unusable today. This is evidence of our rapidly evolving technology and the internet.
It is also likely that the Yottabyte (currently the biggest storage measurement unit), or the proposed hellabyte, will be dwarfed by more significant metrics in the future. Thus, understanding every file size explained above provides a basis for contextualizing future storage capacities.
The image featured at the top of this post is ©A. Solano/Shutterstock.com.