gigabyte (GB)

Contributor(s): Sarah Wilson

A gigabyte (GB) is a measure of computer data storage capacity that is roughly equivalent to 1 billion bytes. A gigabyte is two to the 30th power or 1,073,741,824 in decimal notation. The term is pronounced with two hard Gs. The prefix giga comes from a Greek word meaning giant.

There are two standards for measuring the number of bytes in a gigabyte: base-10 and base-2. The base-10 definition of gigabyte uses the decimal system to show that 1 GB is equal to one to the 10th power of bytes, or 1 billion bytes. This is the standard most storage manufacturers and consumers use today.

Computers typically use the binary form of measurement, referred to as base-2. Base-2 measures 1 GB as equal to 1,073,741,824 bytes. Gigabytes are sometimes referred to as gibibytes in this model. While the discrepancy between base-10 and base-2 measurements wasn't substantial at first, it became more pronounced as vendors began manufacturing storage media with more capacity and caused for some confusion among consumers.

Base-2 vs. Base-10 definition

Gigabyte-size storage options and pricing

There are a number of types of storage media available that provide capacity in the gigabyte range, and those capacities can vary drastically. Some of the most commonly used storage types that provide capacity in this range are hard disk drives (HDDs), flash drives and DVDs. Today, 1 GB translates to approximately 200 songs or 250 10-megapixel photos. Most personal, removable storage devices have capacities ranging from 8 GB to 128 GB.

Cost of a GB of storage

Cost per gigabyte varies among vendors and types of storage media. The cost per gigabyte is higher on a flash drive than it is on a HDD. However, the cost per gigabyte across all vendors and storage types generally lowers year over year. The average price per gigabyte of a HDD in 2005, for example, was $1.24, while in 2014 the price dropped to 3 cents.

Also see gigabit, megabyte, terabyte and exabyte.

This was last updated in March 2015

Continue Reading About gigabyte (GB)

Dig Deeper on Data storage management

Join the conversation


Send me notifications when other members comment.

Please create a username to comment.

Do you think the price per gigabyte of storage will continue to drop? Why or why not?
I do think the price of storage will continue to drop--for both magnetic and solid-state media.

For spinning disk, new techs like shingled magnetic recording (SMR) lets disk makers cram more data into the same space by laying it the surface at an angle. And other techniques, like HGST's use of helium instead of air in the disk enclosure, allows stacking of more platters to increase capacity.

For solid state, watch for TLC NAND flash to start to show up in enterprise flash products. TLC puts three bits of data in each flash cell (vs. one for SLC and two for MLC), upping the capacity of solid-state devices considerably.
Why is this even a question? Of course it will continue to drop. Technology advances in a way that pushes costs continually downward, and that includes the costs of storage. The only likely reasons for this to change are an issue in manufacturing or the introduction of a new method of data storage - the price-per-Gigabyte of Solid State Drives, for example, remains higher than conventional drives. Even so, overall storage prices will continue moving downwards.
I have to agree with James here; this is like asking if PCs are going to get faster or mobile phones are going to get more powerful. 

Let's turn it around -- if you think that the price for gigabyte *isn't* going to drop, whyever do you think that?


File Extensions and File Formats

Powered by: