Bits, Bytes, Megabytes, Gigabytes, Terabytes... what are they?

Understanding Storage Units

Many people know these words. However, many don’t know what they actually mean. Although you will most likely know if you have taken Computer Science classes, many people won’t have.

Bits and Bytes

  • Bit (b): The smallest unit of digital information. It can represent a 0 or 1, true or false, or an electrical switch’s state. A collection of bits forms bytes.
  • Byte (B): A group of 8 bits. Bytes are used to represent a single character in the ASCII character set, and they are the fundamental building blocks for larger data units.

Multiples of Bytes

To handle large amounts of data conveniently, multiple bytes are combined into larger units:

  • Kilobyte (KB): 1 KB is equal to 1,024 bytes, commonly rounded to 1,000 bytes in some contexts. This unit is often used for small text files or simple images.
  • Megabyte (MB): 1 MB equals 1,024 KB, or 1,048,576 bytes. It’s commonly used to describe the size of documents, photos, and MP3 audio files.
  • Gigabyte (GB): 1 GB equals 1,024 MB, or 1,073,741,824 bytes. This unit is widely used for measuring the capacity of storage devices like hard drives and flash drives.

Bits and Bytes in Networking

In networking, data transfer rates are usually shown in bits per second:

  • Kilobit per second (Kbps): Indicates 1,000 bits per second, which is commonly used to describe internet connection speeds.
  • Megabit per second (Mbps): Indicates 1,000 Kbps or 1,000,000 bits per second, commonly used for measuring data transfer rates in network devices.
  • Gigabit per second (Gbps): Indicates 1,000 Mbps or 1,000,000,000 bits per second, commonly used in high-speed network connections.

Large Storage Units

For even larger data capacities, we have:

  • Terabyte (TB): 1 TB equals 1,024 GB, or 1,099,511,627,776 bytes. This unit is commonly used to measure storage on modern hard drives and data centers.
  • Petabyte (PB): 1 PB equals 1,024 TB, or 1,125,899,906,842,624 bytes. This unit is used to describe vast amounts of data in enterprise-level storage solutions.
  • Exabyte (EB): 1 EB equals 1,024 PB, or 1,152,921,504,606,846,976 bytes. This unit is used for massive data storage scenarios, such as data centers managing enormous datasets.

Binary Storage Units

In some cases, usually in computer science and data storage, binary-based prefixes are used instead of the decimal-based prefixes used in the International System of Units (SI). The common binary storage units are:

  • Kibibit (Kibit): 1 Kibit equals 1,024 bits.
  • Mebibit (Mibit): 1 Mibit equals 1,024 Kibits or 1,048,576 bits. Mebibits are commonly used in telecommunication and networking.
  • Gibibit (Gibit): 1 Gibit equals 1,024 Mibits or 1,073,741,824 bits. Gibibits are used to describe high-speed network capacities and data transfer rates. - This is what replit uses to measure storage in Repls, account storage, and Egress usage.
  • Tebibyte (Tibyte): 1 Tibyte equals 1,024 Gibibits or 1,099,511,627,776 bits. It is used in computer memory and storage measurements.
  • Pebibyte (Pibyte): 1 Pibyte equals 1,024 Tibytes or 1,125,899,906,842,624 bits. Pebibytes are used for large-scale data storage in scientific and enterprise applications.
  • Exbibyte (Ebibyte): 1 Eibyte equals 1,024 Pibytes or 1,152,921,504,606,846,976 bits. Exbibytes are used to measure extensive data storage in advanced computing environments.


You now hopefully know all the most commonly used storage types! This knowledge will prove useful in many ways, for example I just wrote this because I had to learn what a GiB was for a project!
I hope this guide helped you!


Hey @MiloCat , I think this should be a wiki.


Sure, maybe @QwertyQwerty88 can make it one?

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