A petabyte is a unit of information equal to one quadrillion bytes, or 1024 terabytes. The unit symbol for the petabyte is PB. The prefix peta (P) indicates the fifth power to 1000: 1 PB = 1000000000000000B, 1 million gigabytes = 1 thousand terabytes The pebibyte (PiB), using a binary prefix, is the corresponding power of 1024, which is more than $12\% $greater ($2^{50} bytes = 1,125,899,906,842,624 bytes$).