Bits to Pebibytes
Binary petabyte class
Pebibyte (PiB) stores 2^50 bytes, i.e. 8 × 2^50 bits. Tape libraries quoting PiB-native cartridges pair naturally with this conversion.
Why not PB?
PB is decimal and undersells PiB by about 12.6% at the same nominal prefix—always echo the unit symbol your vendor contract cites.