GCSE Link: 3.01 (Units of Information)

There is nothing new on this page for A Level. The following tables have been copied over from the page for GCSE.

Table 1 shows the more common prefixes used when describing memory usage.

Table 1

Unit Number of bytes
Kilobyte (kB) 103 = 1,000 bytes
Megabyte (MB) 106 = 1,000,000 bytes
Gigabyte (GB) 109 = 1,000,000,000 bytes
Terabyte (TB) 1012 = 1,000,000,000,000 bytes

Table 2 shows the less common prefixes used when describing memory usage.

Table 2

Unit Number of bytes
Kibibyte (KiB) 210 = 1,024 bytes
Mebibyte (MiB) 220 = 1,048,576 bytes
Gibibyte (GiB) 230 = 1,073,741,824 bytes
Tebibyte (TiB) 240 = 1,099,511,627,776 bytes


How many mebibytes are there in two tebibytes?

2 × 220 = 2,097,152 MiB