Data storage values: 3592-C07

This information center displays data storage values using both decimal (base-10) and binary (base-2) units of measurement.

Decimal units such as KB, MB, GB, and TB have commonly been used to express data storage values, though these values are more accurately expressed using binary units such as KiB, MiB, GiB, and TiB. At the kilobyte level, the difference between decimal and binary units of measurement is relatively small (2.4%). This difference grows as data storage values increase, and when values reach terabyte levels the difference between decimal and binary units approaches 10%.

To reduce the possibility of confusion, this information center represents data storage using both decimal and binary units. Data storage values are displayed using the following format:

#### decimal unit (binary unit)

By this example, the value 512 terabytes is displayed as:

512 TB (465.6 TiB)

Table 1 compares the names, symbols, and values of the decimal and binary units. Table 2 shows the increasing percentage of difference between decimal and binary units.

Table 1. Comparison of decimal and binary units and values
Decimal			Binary
Name	Symbol	Value (base-10)	Name	Symbol	Value (base-2)
kilo	K	10³	kibi	Ki	2¹⁰
mega	M	10⁶	mebi	Mi	2²⁰
giga	G	10⁹	gibi	Gi	2³⁰
tera	T	10¹²	tebi	Ti	2⁴⁰
peta	P	10¹⁵	pebi	Pi	2⁵⁰
exa	E	10¹⁸	exbi	Ei	2⁶⁰

Table 2. Percentage difference between decimal and binary units
Decimal Value	Binary Value	Percentage Difference
100 kilobytes (KB)	97.65 kibibytes (KiB)	2.35%
100 megabytes (MB)	95.36 mebibytes (MiB)	4.64%
100 gigabytes (GB)	93.13 gibibytes (GiB)	6.87%
100 terabytes (TB)	90.94 tebibytes (TiB)	9.06%
100 petabytes (PB)	88.81 pebibytes (PiB)	11.19%
100 exabytes (EB)	86.73 exbibytes (EiB)	13.27%