Binary and data representation - EdexcelData capacity

All data in a computer is represented in binary, whether it is numbers, text, images or sound. The computer software processes the data according to its content.

Part ofComputer SciencePrinciples of computer science

Data capacity

Calculating the number of documents that can be stored on a storage medium can be a straightforward process.

Example

Suppose there are 150 music files, each of which is approximately 6 megabytes in size, and a 1 gigabyte USB memory stick on which these files are to be stored. In order to work out how much storage space is required to store all these files on the USB memory stick, the following calculation can be used:

150 x 6 megabytes = 900 megabytes

To determine whether the USB memory stick has enough capacity to store all 150 music files, the units used for both the files and the storage device need to be the same. The size of the music files is in megabytes, so the capacity of the USB will also need to be converted to megabytes. In this example, the USB memory stick has a 1 gigabyte capacity:

1 gigabyte = 1,000 megabytes

The capacity of the USB memory stick is now expressed in megabytes. The following calculation will determine how many 6 megabyte files this storage device can hold:

1000 / 6 = 166.66 files

As there are 150 music files, they will all fit on the USB memory stick.

This process can be applied to files of any type and size:

File typeTypical sizeQuantity a 1 gigabyte USB memory stick could hold
Word processed document50 kilobytes1 gigabyte = 1,000 megabytes, 1000 megabytes = 1,000,000 kilobytes, 1,000,000 / 50 = 20,000 word processed files
Image file100 kilobytes1 gigabyte = 1,000 megabytes, 1000 megabytes = 1,000,000 kilobytes, 1,000,000 / 100 = 10,000 image files
Video file100 megabytes1 gigabyte = 1,000 megabytes, 1,000 / 100 = 10 video files
File typeWord processed document
Typical size50 kilobytes
Quantity a 1 gigabyte USB memory stick could hold1 gigabyte = 1,000 megabytes, 1000 megabytes = 1,000,000 kilobytes, 1,000,000 / 50 = 20,000 word processed files
File typeImage file
Typical size100 kilobytes
Quantity a 1 gigabyte USB memory stick could hold1 gigabyte = 1,000 megabytes, 1000 megabytes = 1,000,000 kilobytes, 1,000,000 / 100 = 10,000 image files
File typeVideo file
Typical size100 megabytes
Quantity a 1 gigabyte USB memory stick could hold1 gigabyte = 1,000 megabytes, 1,000 / 100 = 10 video files