How many Apple floppies on Softrek?...

Over Labor Day weekend, I had a rare hard drive failure that required a quick fix. In need of a spare 1-2 TB (terabytes) of capacity to ease the reformat/restore, I ran to a local electronics store and got a 1.5 TB USB 3.0 drive for $80. IF BEAR AND I WANTED TO TAKE 1.5 TERABYTES OF STORAGE IN DISK II FLOPPIES WITH US ON SOFTREK, how many 53-foot semi-tractor trailers would be in our convoy? (BONUS: About how much would those floppies cost us in 1981 dollars and in today's dollars?)

I'll end your baited breadth suspense and just show you...


That's right. We would have had to have a convoy of six 53-foot tractor-trailers (the sixth only 2/3 full, or 5.66 trucks' worth) following our Softrek-mobile to provide the storage I bought on Labor Day this year for $80 and that fits the palm of my hand.

But let's take a moment and see how I came up with this "Then & Now" result before looking at the staggering cost of how much this storage would have cost us just 31 years ago...

First, some context: 1 TB (Terabyte) = 1 Trillion bytes (that's 1,099,511,627,780 bytes).

To refresh your memory of bits, bytes, kilo-, mega-, tera-, etc. check out the Byte Converter page at


Since we know that an Apple Disk II floppy drive is about 140 Kilobytes of storage, let's see how many Kilobytes are in 1.5 Terabyte. While you are on the Byte Converter page, you can easily find that 1.5 TB (Terabyte) is equal to 1,610,612,736 Kilobytes (or 1.6+ Billion KB).

So if we divide the number of Kilobytes by 140, we'll get the number of floppies needed to store 1.5 Terabyte (TB). So, 1,610,612,736/140 =, click, crunch, crunch...Whoa! That's 11,504,377 Apple Disk II floppy disks. Something over 11.5 MILLION floppy disks to hold 1.5 Terabytes of data!?


Okay, that is surprising but makes sense when you walk through the numbers. But just how many floppies is it in terms of taking them with us on Softrek? For that, we again turn to the 'Interwebs' and do a bit of digging to determine the volume of a typical semi-tractor-trailer truck... Luckily, somebody asked a similar question at and one very detailed and methodical person answered: What is the carrying volume of a semi truck trailer?.

Based on the detailed estimate by the Wiki.Answers answerer, we find that a reasonable estimate for the volume (storage capacity) of a "long-bed" 53-foot trailer is 4,054.5 cubic feet based on a Volume = Length X Width X Height computation of (53)x(8.5)x(9).

Next step, we estimate the volume of an Apple Disk II floppy. We know they are square and approximately 5.25-inch per side. Not having any old Apple disks on hand, I used a guesstimate of 1/8-inch thick for a typical floppy. Again applying the volume computation that would give us: (5.25)x(5.25)x(0.125) or 3.45 cubic inches per floppy.

Since there are 1,728 cubic inches in a cubic foot (12x12x12) and 3.45 cubic inches in a floppy and there are 11.5+ Million floppies in our convoy, that gives us... click, click, crunch, crunch... a little over 22,937 cubic feet of floppies. To put those floppies in our 53-foot trailers, we'd need 22,937/4,054.5 or approximately 5.66 long-bed semi-tractor-trailer trucks in the Softrek Convoy if we were to take 1.5 Terabytes (TB) of data storage capacity with us in 1982!!!

Ok, and how much would that cost?


While the shear volume of 11.5+ Million floppies needed to provide the storage capacity of 1.5 Terabytes in amazing, it is even more amazing when we look at Then & Now costs. For that, we turn to the Classified Ads in the October 1982 issue of Softalk and to the website of the Minneapolis Federal Reserve Bank.

First, let's figure out how much those 11.5+ Million floppy disks would have cost us in 1982 when we were on the road with Softrek. In the classified ads of the October 1982 issue of Softalk, we find that a box of 10 Verbatim Disk II floppies cost $27.95 or a little under $2.80 per disk. If we multiple that by our number of floppies needed to store 1.5 Terabytes, we find that we would have to write a check for $32,212,254 in 1982 for the same capacity that cost me just $80 today and that fits in the palm of my hand. Now, that's a lot of scratch even by today's standards.

But wait, if we take the Consumer Price Index (CPI) into account, how much would those floppies cost us in today's dollars? For that we need only pop a couple figures into the "What is a dollar worth?" calculator on the home page of the Minneapolis Federal Reserve Bank. When we do that we find that in today's dollars (actually 2012 dollars, as this year's CPI is not yet known), those 11.5+ million floppies rolling along in our hypothetical Softrek convoy would have cost us the equivalent of $76.3 Million of today's dollars! :-/

Now that's simply amazing in anybody's book... or magazine!