Difference Between MB and GB

MB vs GB

MB and GB are terms that are nowadays even used by common man without knowing the real meaning of it. If you feel baffled by the words KB, MB and GB, there is no need to be as they are merely numbers that show the amount of data or the capacity of a computer to store data. Out of the three units of measuring the size of data, KB (Kilo bytes) is the smallest and GB (Giga bytes) is the largest though today there are bigger units such as TB (Tera bytes) are being used with ever increasing memory size of computers. Difference between MB (Mega bytes) and GB is really easy to understand if you try to grasp it just as you learnt measurements in the SI system.

In math, we have digits that are 0-9 and use a decimal system. But in computers, electrical components are either on or off, and hence there are only two digits 0, and 1. Thus it is a binary system in computers. Bit is the smallest unit in computers and it can have either of the two values 0 or 1. (Imagine it as a bulb which is either on or off)

Byte is a string of 8 bits (8 bulbs in a row). This is basically the smallest unit in which data is processed in computers. The largest value of byte is 2X2X2X2X2X2X2X2=256, and to represent bigger numbers, we need to use KB.

Next comes KB which is 2X2X2X2X2X2X2X2X2X2=1024 bytes. This is also referred to as 1000 bytes in the metric system. Clearly binary KB is bigger than decimal KB.

MB is 2 multiplied 20 times or 1048576 bytes. In decimal system it would be 10000000.

GB is 2 multiplied 30 times or 10737741824 bytes or 1 billion bytes. This is when there seems to be a wide difference between binary and decimal system.

The reason why people confuse between MB and GB is that some manufacturers use binary system while others use decimal system. When you buy a hard disc, they tell you it is 100GB, but when you install and partition it into A, B, C, and D, your computer does not show their capacity as 25 GB each but somewhat lesser than this. This happens because your computer calculates storage capacity in binary system while those selling the hard drive calculate it in decimal system. This only means if you have 100GB of data to be stored on your computer, you need at least 110 GB of space in the hard drive.


MB and GB are units of measurement that measure the capacity of any data. They actually tell you the number of bytes of information they contain.

MB refers to one million bytes in decimal system while in binary system it stands at 1024576 bytes.

GB refers to one billion bytes in decimal system while in binary system it means 10737741824 bytes.

For easier understanding, you can think of MB as a gram and a GB as a kilo.