Bordering on the line of “too embarrassingly simple for a blog post,” below is an Excel data rate converter.
I occasionally come across problems where I need to convert between different data rates, typically in streaming video applications. Or I need to convert between storage requirements and streaming rates: For instance, if you are recording a video streamed at 200 megabits per second, how long until you fill up one gigabyte of storage?
In the latter case, the streaming rate is usually expressed in powers-of-ten (one megabit equals one million bits) but the storage is usually expressed in powers-of-two (one gigabyte is equivalent to 2^30 (or equivalently 1024^3) bytes). The official SI name for the second unit is “gibibyte,” but I have never heard anyone use this conversationally, and I can’t bring myself to call it that, either. Informally we call both units “gigabytes” and thus sow confusion.
Usually, to make calculations like these, I create a one-off, poor-man’s conversion spreadsheet. I’ve done it so many times that I’ve definitely come up on the wrong side of this xkcd cartoon — so I finally decided to create this version. It’s probably obvious, but you want to edit the cells with the dotted underlines. I hope you find it useful.