Difference Between Megabyte and Gigabyte

Units help us understand different quantities and maintain track of how much a thing is. Digital information is also measured in units and some standard units are described using a basic unit called bytes. A gigabyte is formed of two words Giga and byte. Here, Giga means ten raised to the power of ten. The use of prefixes like these is prevalent in measurement, for example, a kilo is a prefix that means one thousand. In terms of Megabyte and Gigabyte, the base word is byte and prefixes are Mega and Giga respectively.

Megabyte vs Gigabyte

The main difference between Megabyte and Gigabyte is that a megabyte means 1 million bytes of data whereas a gigabyte is one billion bytes of data. The two prefixes mega and Giga are multipliers with values of 10 raised to the power of nine and Giga means 10 raised to the power of six respectively.

Megabyte vs Gigabyte

According to SI units’ definition, megabyte 1 million bytes but in computing different definitions are used. According to one definition, one megabyte equals two raised to the power 20 bytes. The definition is used by Microsoft to measure computer memory. It also has a mixed definition in which 1 megabyte equals 1000 multiplied by 1024. It is used to measure the capacity of an HD floppy disk.

A gigabyte is a unit that is also used to measure memory. It is used to measure digital memory. The SI units define it as one billion bytes, but it also has some other definitions based on the same bases as megabytes. It is defined in terms of a base of two raised to the power of thirty. The definition in terms of base two is used by Microsoft to define computer memory.

Comparison Table Between Megabyte and Gigabyte

Parameters of ComparisonMegabyteGigabyte
SI unit definitionIt is equal to one million bytes.It is equal to one billion bytes.
Definition with base two1 MB equals 1,048,576.1 GB equals 1,073,741,824.
Mixed definitionIt has a mixed definition which equals 1000*1024.It has no mixed definition.
ComparisonIt is a lesser quantity compared to GigabyteIt is a greater quantity compared to Megabyte.
ExampleOne YouTube video of 5 minutes with 1080p quality equals 100MB.The size of the DVD is 4.5GB if it is single-layered.

What is Megabyte?

A unit used to measure digital information with a value equal to a million bytes is called a megabyte. The basic unit of measurement of digital information is byte but due to the need for other definitions to describe larger amounts of digital information megabyte was adopted. Megabyte has different definitions as well. It is also defined in terms of a base of two. When we raise the power of two to twenty it equals 1,048,576. The value is near to 1 million and is used by Microsoft to define computer memory.

The mixed definition of megabytes includes two concepts together. In this method, we multiply one thousand with one thousand twenty-four. It equals 1024000. This mixed-method is used to measure the capacity of HD floppy disk. The disk with a memory of 1.44MB is equal to 1474560 (the size is 3.5 inches). The difference between the capacity is because of the fact that this definition is used to describe the formatted memory.

Megabyte is given a standard definition by the international system of units which is equal to 1 million bytes but the term is not widely accepted due to the reason that there are multiple definitions as described above. These definitions are in use due to convention and historical reasons of convenience.

What is Gigabyte?

Gigabyte is another unit that evolved to measure larger quantities. It is also a multiple of a byte. One gigabyte is equal to one billion bytes, which is defined according to the International System of Units. The definition which uses base two to define the quantity is used by Microsoft to define computer memory. The definition which uses the base 10 is strictly used to define a gigabyte as directed by IEC (International Electrotechnical Commission).

The advent of the gigabyte range caused a lot of confusion as earlier decimal prefixes. The controversy arose due to the gigabyte specification being lesser than those expressed by decimal prefixes. The value of one gigabyte is equal to ninety-three percent of Gibibyte which is reported by the computer operating systems to be lesser. If the specification on the label says 400 GB is equal to only 372 Gibibyte. It causes confusion as operating systems report mebibyte as a gigabyte. 

The lawsuit against manufacturers by consumers has ended in favor of manufacturers as the court held the value of one gigabyte equal to ten raised to the power of nine. The quiet dismissed the binary definition over the decimal definition and declared it to be the legal definition.

Main Differences Between Megabyte and Gigabyte

  1. Megabyte and gigabyte are both multiple the byte which is the basic unit for digital information but they differ in the numbers they define.
  2. A megabyte is smaller in comparison to a gigabyte as a megabyte only equals 10 raised to the power of six and a gigabyte equals 10 raised to the power of nine.
  3. One megabyte can be defined as a mixed value that equals 1000 multiplied by 1024 whereas a gigabyte has no such definition.
  4. The legal definition of one Gigabyte is equal to 10 raised to the power of nine, whereas Megabyte has no legal definition as such.
  5. Different versions of megabytes are used to define digital information whereas the SI definition for a gigabyte is considered standard.


Due to the change in usage and the need for condensed form to define large quantities we invent a different form of units. Megabyte and Gigabyte are examples of such condensed forms. The basic unit for both of them is bytes. One differs from the other in terms of the prefixes that give different values. The mega prefix is nothing but a multiple which equals 1 million whereas Giga is equal to 1 billion. These definitions are in accordance with the international system of units and are called decimal units.

 Different definitions are in use such as the mixed definition of megabytes which equals 1024000 and is used to define the storage of HD floppy disk. The binary definition is used by Microsoft to define the memory computer disk.


  1. https://heinonline.org/hol-cgi-bin/get_pdf.cgi?handle=hein.journals/auslwlib23&section=12
  2. https://link.springer.com/chapter/10.1007/978-1-4471-2099-5_31
  3. https://dl.acm.org/doi/abs/10.1145/844128.844163

Help us improve. Rate this post! Total (0 votes,average: 0)

About the Editorial Staff

Editorial Staff at Ask Any Difference is a team of experts in the field of "Difference Between" topics and led by Sandeep Bhandari, Piyush Yadav and Chara Yadav. Trusted by over 1.5 million readers worldwide
PinterestLinkedIn, Facebook