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NIST binary

In 1995, the National Institute of Standards & Technology defined a new standard of measurement that accurately reflects the difference between decimal and binary numbers. When referring to true binary numbers, the traditional kilo, mega, giga, etc. designations were changed to kibi, mebi, gibi, etc. (see table below). The names are the first two letters of the word plus "bi" for binary. For example, kibi means "kilo binary" and mebi means "mega binary" and so on.

For example, one million bytes would be expressed as one "megabyte" (MB) for the decimal number 1,000,000 (106), but one "mebibyte" (MiB) for the binary number 1,048,576 (220).

Will It Catch On?
After more than a decade, NIST measurements have not become mainstream, but are used when absolute precision is required. See binary values.


 BITS in:
 Decimal         NIST Binary

 kilobit (Kb)    kibibit (Kib)

 megabit (Mb)    mebibit (Mib)

 gigabit (Gb)    gibibit (Gib)

 terabit (Tb)    tebibit (Tib)

 petabit (Tb)    pebibit (Pib)

 exabit  (Eb)    exbibit (Eib)

 zettabit (Zb)   zebibit (Zib)

 yottabit (Yb)   yobibit (Yib)


 BYTES in:
 Decimal         NIST Binary

 kilobyte (KB)   kibibyte (KiB)

 megabyte (MB)   mebibyte (MiB)

 gigabyte (GB)   gibibyte (GiB)

 terabyte (TB)   tebibyte (TiB)

 petabyte (TB)   pebibyte (PiB)

 exabyte  (EB)   exbibyte (EiB)

 zettabyte (ZB)  zebibyte (ZiB)

 yottabyte (YB)  yobibyte (YiB)





binary values

The following table shows the decimal values of binary numbers. Just as the largest value in a group of decimal digits is expressed as all 9's, the largest value in a group of binary digits is all 1's. A decimal digit provides 10 distinct values (0 through 9), but a binary digit has only two (0 or 1). See NIST binary and space/time.


 COMMON BINARY STRUCTURES

 Bits  Maximum Decimal Value
   4     16
   8    256
  15    32K (kilo)
  16    65K (kilo)
  24    16M (mega)
  32     4G (giga)
  48   256T (tera)
  64    16E (exa)
 128   1,600,000,000,000,000,000E (exa)


 BINARY VALUES FROM 1 TO 64 BITS

        Total   Largest Number
 Bits   Values  (Total values -1)
  1        2              1   (1)
  2        4             11   (3)
  3        8            111   (7)
  4       16           1111  (15)
  5       32         1 1111  (31)
  6       64        11 1111  (63)
  7      128       111 1111 (127)
  8      256      1111 1111 (255)
  9      512    1 1111 1111 (511)

 10    1,024   1K (kilo)     11 1111 1111
 11    2,048   2K           111 1111 1111
 12    4,096   4K          1111 1111 1111
 13    8,192   8K        1 1111 1111 1111
 14   16,384  16K       11 1111 1111 1111
 15   32,768  32K      111 1111 1111 1111
 16   65,536  65K     1111 1111 1111 1111
 17  131,072 128K   1 1111 1111 1111 1111
 18  262,144 256K  11 1111 1111 1111 1111
 19  524,288 512K 111 1111 1111 1111 1111

 20    1,048,576    1M (mega)
 21    2,097,152    2M
 22    4,194,304    4M
 23    8,388,608    8M
 24   16,777,216   16M
 25   33,554,432   32M
 26   67,108,864   64M
 27  134,217,728  128M
 28  268,435,456  256M
 29  536,870,912  512M

 30    1,073,741,824    1G (giga)
 31    2,147,483,648    2G
 32    4,294,967,296    4G
 33    8,589,934,592    8G
 34   17,179,869,184   16G
 35   34,359,738,368   32G
 36   68,719,476,736   64G
 37  137,438,953,472  128G
 38  274,877,906,944  256G
 39  549,755,813,888  512G

 40    1,099,511,627,776    1T (tera)
 41    2,199,023,255,552    2T
 42    4,398,046,511,104    4T
 43    8,796,093,022,208    8T
 44   17,592,186,044,416   16T
 45   35,184,372,088,832   32T
 46   70,368,744,177,664   64T
 47  140,737,488,355,328  128T
 48  281,474,976,710,656  256T
 49  562,949,953,421,312  512T

 50    1,125,899,906,842,624    1P (peta)
 51    2,251,799,813,685,248    2P
 52    4,503,599,627,370,496    4P
 53    9,007,199,254,740,992    8P
 54   18,014,398,509,481,984   16P
 55   36,028,797,018,963,968   32P
 56   72,057,594,037,927,936   64P
 57  144,115,188,075,855,872  128P
 58  288,230,376,151,711,844  256P
 59  576,460,752,303,423,480  512P

 60   1,152,921,504,606,846,976  1E (exa)
 61   2,305,843,009,213,693,952  2E
 62   4,611,686,018,427,387,904  4E
 63   9,223,372,036,854,775,808  8E
 64  18,446,744,073,709,551,616 16E





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