Units of Big Data

Below is a table of units of Big Data. Terms and amounts of data are given along with examples of what that amount of data may be for reference. Symbols in the table are SI units, but you may see different symbols in common usage for some of these units.

Name Symbol Quantity Approximate Equivalents
byte B 10000 B = 1 B A single character such as “q” or “3”
kilobyte KB 10001 B = 1000 B 1000 letters – about 125 words
megabyte MB 10002 B = 1000 KB A novel – about 125,000 words or one color image
gigabyte GB 10003 B = 1000 MB Amount of memory in smart phone or computer – about 1000 novels -about 10 years of constant reading
terabyte TB 10004 B = 1000 GB A huge library of books – about 100,000 volumes
petabyte PB 10005 B = 1000 TB All the books ever published
exabyte EB 10006 B = 1000 PB Number of stars in the galaxy
zettabyte ZB 10007 B = 1000 EB The entire contents of the Internet in 2016

You can see that each of these names is for a quantity 1000 times bigger than the previous name. In terms of data storage, the first computer floppy disks held a few hundred KB, early hard drives had tens of MB capacity, and in 2017, flash drives (thumb drives) held 250 GB of data.

Looking at this table, you can see that the 100 TB of data generated each day by FaceBook users is truly Big Data, but still is only about a billionth of the entire Internet.