Kilo mega giga tera peta exa

Here is a summary of memory size names and their corresponding address sizes. Many people memorize this type of information naturally through working with computer technology over time or during a professional career.

Large number abbreviations

Practicing with Quizlet

If you want to memorize these values, there are flash cards and other self-training exercises on the Quizlet page.

The page tests your knowledge of the smaller sizes (K, M, G, T), how these sizes are related (i.e. a terabyte is a thousand billion bytes), and how they relate to memory sizes (a TB needs an address approximately 40 bits long).

Address Size Shortcut

Here is a simple shortcut for estimating the number of bits required to address storage of a given size.

103 ~ 210

To put this into practice, we do the following:

  1. Count the number of sets of three zeros (the “thousands”) in the storage size.
  2. Multiply the number of thousands by ten

Let’s work out an example with a terabyte: a trillion-byte memory.

  1. In a trillion (1,000,000,000,000) there are 4 sets of three zeroes
  2. Multiply 4 by 10, and we get approximately 40 bits.