Binary is bits. 2^10 is bits. 2^10 = 1024 bits. 1024^1 is 1 kilobyte. Yes, 1 kilobyte = 1024 bytes.
"There are 1024 bytes in a kilobyte (KB) using conventional metrics"
1024 bytes (KB) is far from conventional.
There are 4 commissions supporting 3 different systems to express units of 1000 for storage:
• 1 kilobyte (kB) 1000 bytes
• 1 kibibyte (KiB) 1024 bytes
• 1 kilobyte (KB) 1024 bytes
The "conventional" system you're citing is the JEDEC standard because you used "KB" to express 1024 bytes. JEDEC is unconventional for a couple reasons. First, JEDEC as a base-2 (binary) system uses the same metric prefixes as the IEC base-10 (decimal) system: KB, MB, GB. There is nothing wrong with this except it taps out at GB. This is why...for consistency..."B" is decimal and "iB" is binary.
Since the JEDEC stops measuring at GB, it has no binary measure for terabyte. Since JEDEC has no binary for terabyte, the JEDEC falls back to the base-10 measures of the IEC. Therefore, at some point within JEDEC, you...figuratively speaking...lose bytes. For example, if you upgraded RAM in a Windows server from 512 GB to 1 TB, you'd lose bytes from 1 metric to the other.
Second, with the confusingly-same prefixes, why use JEDEC to clarify 1.25 TB? The more conventional IEC base-2 (binary) system is right there with distinctive prefixes as well as being fully-expressed up to the yobibyte (YiB) (1024^8)? If Cox needs to clarify 1.25 TB as binary value, Cox should notate as 1280 GiB...not 1280 GB.
However, the overall point is why would Cox use 2 different systems to reference 1 limit? Cox cited "1.25 TB" and then uses 1280 GB as a parenthetical to...I suppose..."clarify." Why...for who? Is Cox interpreting for our binary-only subscribers? You had to multiply 1250 GB by 1.024 to justify 1280 GB, so are our decimal-only subscribers suppose to divide 1280 GB by 1.024 to understand the data cap?
"Hey, Cox...I don't know what a "TB" is but you charged me $10 for exceeding 1280 gigabytes...but I hadn't exceeded 1280 gigabytes!" [No...you're supposed to reduce this limit by dividing 1280 GB by 1.024. This is why we're taking more of your money.]
My original comments were aimed at consistency. I know there are websites and formulas to interpret decimal-to-binary and vice versa for storage; however, Cox needs to be consistent. For example, in addition to the Data Cap, Cox uses MB and GB to express blocks of additional data ($10), maximum mailbox limits and maximum email sizes. Where are the "conventional" interpretations for these limits? Why would Cox arbitrarily use a binary value...1 time...to "clarify" 1.25 TB? Why not clarify all limits with both numbering systems? Also on the same page, Cox had to explain their measurements:
Data Plans: A Data Plan is the amount of data included within your monthly Internet package, measured in Gigabytes and Terabytes...
Cox had to explain gigabytes and terabytes to measure data. Cox only uses MB, GB and TB to express this data. As a binary system, only JEDEC uses MB, GB but not TB. Since there is no measurement for terabyte with JEDEC, one would have to presume (logically), GB and TB are decimal measurements. If not, Cox should use KiB, MiB, GiB, TiB, etc.
Therefore, based on the consistency of their explanations, prefixes and system of measurement: How does 1.25 TB equal 1280 GB? It wasn't a mathematical question; it was a notational question.