How many punched cards fit in a flash drive?

Consider how much data can fit on your thumbnail.
Here's a 16 GB microSD card.
It weighs so little that a jewler's scale can barely weigh it: about 0.2g, 0.010 oz.

The microSD card fits inside the college logo
It's barely larger than the chad of this hand-punched card for a programmable calculator
About the size of 9 holes of this Remington Rand card
A microSD card is small even compared to an IBM system 3 card


That 16 GB microSD card is 31244288 512-byte logical blocks for 15,997,075,456 bytes.

  1. A standard IBM tabulator punched card has one character per column,
    even if it's a multipunched per this chart
    Without trailing blank suppression, that's 80 bytes per card.
    The microSD card holds the equivalent of 199,963,443 cards (99,981 boxes of 2,000 cards).

  2. For a punched card with pure binary in columns 1-72
    following the IBM 1130-1800 binary format
    (leaving columns 73-80 for the traditional id & sequence number),
    that's 12 rows x 72 columns = 864 bits, or 108 octets.
    The microSD card holds the equivalent of 148,121,069 cards (74,060 boxes of 2,000 cards).

  3. For a punched card with pure binary in all 80 columns, that's 12 rows x 80 columns = 960 bits, or 120 octets
    The microSD card holds the equivalent of 133,308,962 cards (66,654 boxes of 2,000 cards).

  4. The Remington Rand card has 90 characters @ 6 bit = 540 bits or 67.5 octets.
    The microSD card holds the equivalent of 236,993,710 cards (118,496 boxes of 2,000 cards).

  5. The IBM system 3 card with 128 characters @ 6 bits = 768 bits or 96 octets.
    The microSD card holds the equivalent of 166,636,202 cards.

  6. The IBM system 3 card with 96 characters @ 6 bits = 578 bits or 72 octets.
    The microSD card holds the equivalent of 222,181,603 cards.
Of course, double that for a 32 GB microSD card!

When pronouncing large numbers such as million or billion
be aware that the names of large numbers differ in the USA and the UK