Areal Density

What Does Areal Density Mean?

Areal density is the measurement of storage units per square inch, or, more generally, the measurement of storage capacity relative to physical dimensions.


Areal density is sometimes used interchangeably with the terms area density and surface density.

Techopedia Explains Areal Density

Areal density is an important idea in IT. For an easy example of areal density, think of a small piece of storage media. Say the disk is one square inch in terms of its physical size. If that disk has 1 GB of storage capacity, the areal density measurement is 1 GB per square inch.

Areal density is a useful term in looking at the relative storage capacity of physical storage media like magnetic tapes or disks and optical disks. Reports from the IT industry over time have shown how areal density improves at a dramatic rate. The ability to pack more digital storage capacity into smaller disks and devices is a large part of what has driven improvement in the hardware industry and other parts of the tech business.


Related Terms

Latest Storage Terms

Related Reading

Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…