How Computer Memory is Measured | Computer Memory Overview

Computer memory is what stores information both permanently and temporarily. Computer memory, in the form of integrated circuits, refers to the storage space located in the computer hardware. It’s the part of a computer that stores the data (to be processed) and instructions (for data processing). Since it’s the storage we’re talking about, it’s important to know how much information can a particular memory unit hold, and the only effective way to know that is to learn ‘how computer memory is measured’. Maybe, you’ve been able to guess that this article is all about computer memory measurement.
Where the human brain is the biological version of memory, computer memory is the technical one that stores information using two distinct mechanisms such as ROM (Read-Only Memory) and RAM (Random Access Memory). These devices use integrated circuits, and different operating systems, hardware, and software applications use them for functioning. Did you get anywhere close to the way how computer memory is measured? Well, you will soon…
But before you get to learn the measurement techniques, you need to gather some insights into the entire ‘memory’ thing that a computer runs on and users benefit from.
Computer memory that we’re familiar with can be volatile and non-volatile, or RAM and ROM respectively, just in case you’re interested in knowing what they’re called in technical terms.
Volatile memory or RAM relies on the power that a computer runs on. It means this kind of memory loss what’s stored as a device loses its power. You might have seen that some of your works become unavailable once the computer reboots or shuts down. Often referred to as NVRAM, non-volatile memory keeps contents in case of power outage or sudden reboots. Did you ever hear of EPROM? It’s a physical form of non-volatile memory. Now, you want to know how one can measure one’s computer memory.
It all starts with the units, not exactly like the different units we use in our real world. Here’re the units of memory measurement.

  • Binary Digit (Bit)
  • Byte
  • Kilobyte (KB)
  • Megabyte (MB)
  • Gigabyte (GB)
  • Terabyte (TB)
  • Petabyte (PB)
  • Exabyte (EB)
  • Zettabyte (ZB)
  • Yottabyte (YB)

About Binary Digit (Bit) and Byte

The bit is the smallest unit of measurement which has a binary value of 0 or 1. Four bits when combined/grouped equally to one nibble while eight of them, when combined/, grouped make a Byte. Computers are designed to manipulate bits in groups or combinations of a fixed size which, in technical jargons is known as words. Users barely work with one bit of information at a time as it’s the smallest increment of computer data. On the other hand, a byte contains usable information like one particular ASCII character.
It’s easy for a lot of users to get confused about the notations for bits and bytes. It’s because of the abbreviations and names for the numbers of bytes. Let’s get this confusion straight to your clear understanding.
The numbers of bits when abbreviated use “b” in the lower case and not the uppercase. As you’ve learned that one byte equals eight bits, keeping this in mind can be crucial to your understanding of the whole thing.
You can take the advertisement for a broadband connection package into consideration to understand this. If your connection comes advertised with 3.0 Mbps as the download speed, you should take that the speed is going to be 0.375 megabytes/second or 3.0 megabits/second. Furthermore, it would be expressed as 0.375 MBps.

Understanding the Distinction between Binary and Decimal Systems

Because computers use the binary (base two) method which is unlike the decimal (base ten) method, a kilobyte (KB) contains 1,024 bytes, not 1,000 bytes as many might have mistakenly regarded so far. So, 1 MB contains 1,048,576 bytes or 1,024 kilobytes instead of 1,000,000 bytes or 1,000 kilobytes. Similarly, 1 gigabyte contains 1,024 megabytes, or 1,073,741,824 bytes instead of 1,000 megabytes or 1,000,000,000 bytes. Here’s the mathematical calculation.

Our decimal method is based on 10

101 = 10; 102 = 10 x 10 = 100; 103 = 10 x 10 x 10 = 1,000; 106 = 1,000,000

Computer’s Binary Digit System is based on 2

21 = 2; 22 = 2 x 2 = 4; 23 = 2 x 2 x 2 = 8; 210 = 1,024; 220 = 1,048,576

How Do Manufacturers and Computers Define Memory Capacity?

Hard drive manufacturing companies take a different route other than binary digits or its subsequent larger units. Using a decimal system, manufacturers define the space a particular hard drive comes with. You’ll see 1 MB is described as one million bytes, 1 GB as one billion bytes, etc. So, you can now easily understand why there’s always a difference in the numeric expressions of the capacity of a hard drive in the particular of the manufacturer and the system of your computer.
For example, a 10GB HDD based on a decimal system stores technically 10,000,000,000 bytes The binary system of a computer, in terms of the way it’s defined, should say that the capacity is 10,737,418,240 bytes. But, the computer acknowledges only 9.31 GB instead of 10 GB. A beginner would easily call it a sign of malfunction which is not. The only thing that happens here is the different angles the memory is defined.

A Table Showing the Computer Memory Assessment

Here’s a list of all units along with their numeric expressions for the subsequent ones.

Unit + Amount Equivalent Unit
1 Bit 0/1
8 Bits 1 Byte
1024 Bytes 1 Kilobyte
1024 Kilobytes 1 Megabyte
1024 Megabytes 1 Gigabyte
1024 Gigabytes 1 Terabyte
1024 Terabytes 1 Petabyte
1024 Petabytes 1 Exabyte
1024 Exabytes 1 Zettabyte
1024 Zettabytes 1 Yottabyte

Here’s another list of the units expressed for their byte equivalents.

Units Equivalents
1 KB 1,024 Bytes
1 MB 1,048,576 Bytes
1 GB 1,073,741,824 Bytes
1 TB 1,099,511,627,776 Bytes
1 PB 1,125,899,906,842,624 Bytes

A Few Practical Examples of Computer Memory

Some of the most commonly used units of computer memory are megabytes and gigabytes. So, in terms of practical applications, we often see the following things.

  • 1 megabyte provides adequate space for a medium-sized novel.
  • 1 terabyte (1024 gigabytes) provides space for the books and documents of a typically large library. The amount of data can also be equivalent to what as many as 1,610 CDs can store.
  • 1 petabyte contains 1024 terabytes which can be equal to the data on roughly 223,100 DVDs (if written).

It may sound rather astonishing that the number of DVDs mentioned here makes a stack which can be as tall as 878 feet. In addition, if CDs are used in place of DVDs, the stack would run as tall as 1 mile.
So, you’re quite familiar with the process of how computer memory is measured. This knowledge should be helpful as you plan on getting a storage device or unit for your particular needs, or you’re just curious.