The following units of measure are used to define storage and transmission capacities. For measurements of a meter, see metric system. See binary values and NIST binary.

                          10 to the
   SPACE - Bits/bytes     power of

   Kilo  (K)  Thousand       3
   Mega  (M)  Million        6
   Giga  (G)  Billion        9
   Tera  (T)  Trillion      12
   Peta  (P)  Quadrillion   15
   Exa   (E)  Quintillion   18
   Zetta (Z)  Sextillion    21
   Yotta (Y)  Septillion    24
                                    10 to the
   TIME - Fraction of a second       power of

   Millisecond (ms)  Thousandth       -3
   Microsecond (µs)  Millionth        -6
   Nanosecond  (ns)  Billionth        -9
   Picosecond  (ps)  Trillionth      -12
   Femtosecond (fs)  Quadrillionth   -15
   Attosecond  (as)  Quintillionth   -18
   Zeptosecond (zs)  Sextillionth    -21
   Yoctosecond (ys)  Septillionth    -24


   Storage/Channel Capacity Measured in

   CPU word size             bits
   Bus/Channel size          bits
   Disk, tape                bytes
   Overall memory capacity   bytes
   SIMM and DIMM modules     bytes
   Individual memory chip    bits


   Transmission/Transfer Speed Measured in

   Network line/channel      bits/sec
   Disk transfer rate        bytes/sec
   Disk access time          ms
   Memory access time        ns
   Machine cycle             µs, ns
   Instruction execution     µs, ns
   Transistor switching      ns, ps, fs