Decimal kilobytes vs. binary kilobytes: Which one should I use?

Can someone please clarify what

801,203 kB

means? Is that roughly 801 kB?

If so—how did they end up with a decimal point and where does this extra 0.203 kB come from?

Alternatively, if it’s actually 801,203 KB, why isn't it listed as 801 MB?

Not sure I’m even following the question here.
Why wouldn't kilobytes be allowed to have a decimal point?
Like, if you're looking at 801,203 bytes, that's just 801.203 kilobytes.
(Assuming we're going by the 1 kB = 1000 B rule. Same logic applies if you use the 1024 B standard)

Of course, there's also that other possibility you mentioned, where the comma is just being used as a thousands separator. But if that's the case, why didn't they just list it in MB? You'd have to ask whoever actually published that data...

My bill shows an internet data usage of 801,203 kB—which leaves me stuck in a bit of a limbo. It feels far too low if we're talking about 800 KB, yet obviously way too high if it's meant to be 800 MB.

Thanks, 🙂

Also, I have no idea why I spent tonight convinced it had to be a whole number :/.

Decimal notation is used for "accuracy," which is why you see differences when converting between MB, GB, and TB. When you convert units, data seems to "shrink" during the process—which is why a 1TB hard drive shows up as roughly 900-something GB. But when it comes to your bank account, don't expect those numbers to be perfectly precise. It's better to just head to the customer service portal to verify your actual transaction history; I’d bet money the real status looks different. Even an 800MB difference matters, yet even a decimal point can shift things. For some reason, these conversions aren't always consistent. Why should they be?