Figuring out how many megabytes go into gigabytes? [duplicate]

I needed to figure out how many requests could be made with 1000 GB of traffic if each request took 1MB on average. I quickly did the math on paper, and then as a second thought plugged it into Google. To my surprise, Google's answer is different than mine.

My way:

`1,000 gigabytes = 1000*1024*1024*1024 bytes`

Divide by `1 megabyte = 1024*1024 bytes` to get:

`(1000*1024*1024*1024)/(1024*1024) = 1,024,000`

`1000 gigabytes / 1 megabyte`

Output: `1,000,000`

Am I wrong, or is Google wrong?

• Be specific: Do you have 1000 GiB or 1000 GB worth of traffic? Do you have 1 MiB or 1 MB requests? – slhck Jul 29 '14 at 18:40
• – Adam Jul 29 '14 at 18:42
• @Adam Oh wow, `mebibytes` and `kibibytes`? I need to go rethink my life now. :P – Nate Jul 29 '14 at 18:47
• What? 1000 ≠ 1024? Next thing, you'll be telling me that π ≠ 3. – Scott Jul 29 '14 at 20:21
• This xkcd will clear things up – Nick T Jul 30 '14 at 4:02

Neither of you are wrong, you just asked Google a different question from your actual question. If you had explained to Google that you meant GiB and MiB, it would have given the answer you expected.

Try this: `1000 GiB / 1 MiB`

• Google always knows.. :-) – Nate Jul 29 '14 at 18:55
• To clarify, these are pronounced `gibibytes` and `mebibytes` respectively. The base-ten version is pronounced `gigabytes` and `megabytes` respectively. – user530873 Jul 29 '14 at 22:59
• The base-ten version is pronounced `metric gigabytes` and `metric megabytes` respectively. – Mark Jul 30 '14 at 10:57
• Why is 1KB so massively commonly used to refer to 1024 bytes, when the standards say it's 1000 bytes? What made the standards people come up with something that contradicted such a widely used thing. – Jonathan. Jul 30 '14 at 12:50
• @user530873: Not if you want people to actually say them, they're not. :P I refuse to say the word "gibibyte" unless i'm consciously trying to sound stupid. – cHao Jul 30 '14 at 13:48

This is a topic that has been heavily debated, and popularized by hard drive manufacturers (and Wikipedia multiple times). There are two sets of standards for binary prefixes, which pretty much contradict each other. JEDEC uses KB, MB and GB while the IEC uses KiB, MiB and GiB. Here, powers of 1024 are used.

For decimal prefixes (IEC), powers of 1000 are used. Linux, Mac and Google use the 1000 powers when representing KB, MB and GB, while Windows (and Bing) use the 1024 powers for representing KB, MB and GB.

Outside of a small niche, the IEC binary prefixes will seldomly be used. It's worth noting that is was only until recently Google showed that 1024 bytes in to 1 KB.

It's worth noting that the prefixes are used for different things. A 10 Mbps connection is 10,000,000 bits per second a 1.44 MB floppy is 1,400,000 bytes.

• That's what I was saying also, about google. They showed up 1024 a few months back. I guess they captured my swearing when I searched "*********…*** google 1KB is not 1024B you **********…****" – user127350 Jul 29 '14 at 23:05
• +1 The comments and top answer seem to be under the impression that using KB when one means KiB is wrong. But this is the correct answer. There are two different standards. Adding the new prefixes didn't help as they could because they were used for for the less common usage. "1024 kilobytes to the byte" predates "1000 kilobytes to the byte" by a long time, with the latter mostly being used in networking and sales of storage (to make it seem like the customer was getting more). Until relatively recently, even the IEC used 1024 KB per MB. – trlkly Jul 30 '14 at 5:05
• I'd also point out that Linux often uses MiB and the like so that the numbers match up with Windows, even if the units don't quite match. And this is still not consistent, as many apps still use the more common terms. To tell the truth, I think the IEC screwed up. Using the metric prefixes for binary was more common, so the new abbreviations should have referred to the decimal concept. And they should have avoided cutesy names like "mebibyte," terms people will think strange to use officially. It's been 7 years, and still the binary prefixes haven't caught on in the general public. – trlkly Jul 30 '14 at 5:13
• @trlkly I agree with everything you said. Not many people I know even have heard of a 'kebibyte'. – Justin Krejcha Jul 30 '14 at 5:14
• The problem is cases where you really do want mega to be a million. For example, a 100Mbps Ethernet cable really does carry 100,000,000 bits per second. – David Schwartz Jul 30 '14 at 18:48