Kilo Bytes Per Second vs. Kilo Bits Per Second (KBps vs. kbps)
Well this post tries to clarify the confusion that many have regarding KBps and kbps (I was one too). If you read through this post it will make a lot of things clear.
Measure of file size: KBps
File size i.e. how big the file or how much space a file occupies in the hard disk measured in terms of KiloBytes (KB upper case “K” and upper case “B”). In computing terms the upper case “K†stands for 1024. 1024 is computed from 210. (2 power 10). 2 denote the number of characters in the binary system which is used to store data in the disc (ones and zeroes).
Other abbreviations like mega, giga and terra also use the base as 1024,
1KB (KiloByte) = 1024 Bytes (approximately 1000 Bytes)
1MB (MegaByte) = 1024 KB (approximately 1000 KiloBytes or 1 million Bytes)
1GB (GigaByte) = 1024 MB (approximately 1000 MegaBytes or 1 billion Bytes)
1TB (TerraByte) = 1024 GB (approximately 1000 GigaBytes or 1 trillion Bytes)
Measure of data transfer speeds: kbps
Data transfer speed over the networks (including the internet) is calculated in terms of bits per second: kilobits (kb small case “k†and small case “bâ€). The higher the kbps i.e. more the bits transferred per second, more the speed, faster the network/connection. Here k stands for 1000 (103 )
1 kbps (kilo bits per second) = 1000 bits per second
1 Mbps (mega bits per second) = 1000 kilo bits per second.
1 Gbps (giga bits per second) = 1,000 mega bits per second.
ISP bandwidth and download speeds
The most common confusion caused by the similarity of KBps and kbps is when it comes to internet bandwidth and download speeds. People often complain that their ISP promised 512kbps connectivity but they are seldom able to download any file at 512 KBps. They fail to notice the difference in cases of the units and hence think their ISP is cheating them or offering them poor quality service. As mentioned earlier data transfer speeds are always calculated in terms of kilo bits per second (kbps) so an ISP connectivity of 512 kbps promises of transfer of at the max 512 kilo bits per second.
On the other hand, file size measure is always in Kilo Bytes and thus download speeds are always calculated based on how many Bytes per second are downloaded and hence Kilo Bytes per second (KBps). KBps and kbps are not interchangeable.
So an internet connectivity of say 512kbps can never achieve a download speed of 512 KBps. To calculate the maximum download speed of a “X kbps†connection, we need to use a simple formula as below.
Download KBPS speed = (Kbps value*1000) /8)) / 1024.
I.e. For a connectivity of 512 kbps
kbps value * 1000 = 512 * 1000 = 512000
512000 / 8 = 64000
64000 / 1024 = 62.5 KBps
Therefore theoretically an internet connection of 512kbps bandwidth can download at a speed of 62.5 KBps
If you don’t want to go through all the hassles of the above formula, just multiply the kbps value with 0.1220703125 to get the KBps value.
512 kbps * 0.1220703125 = 62.5 KBps. Simple!
| Internet connectivity | Download speed (approx) |
| 256 kbps | 31.3 KBps |
| 384 kbps | 46.9 KBps |
| 512 kbps | 62.5 KBps |
| 768 kbps | 93.8 KBps |
| 1 mbps ~ 1000kbps | 122.1 KBps |
I have mentioned download speed as approximate because they will vary (always reduce) by 15 – 20% due to network signal loss, computer hardware overheads etc. So for realistic, real world figures always reduce 15 – 20% from the computed KBPS download speeds
Now I guess the confusion of kbps and KBps has cleared away. Just remember when you talk in terms of network it’s always bites per second (bps) and when you talk in terms of storage and files its always Bytes per second (Bps). And next time you won’t complain when your 512 kbps connection does not give you download speeds of 512KBps because now you know why 
this article is really valuable for those,who really wants to charge themselves with the latest technology
Real good going. dat was very enlightening..& valuable!
this article really helped me!
thank u!
excellent stuff, really helpful…
Your article is very helpful. Lately I have been experiencing quite low download speeds and was convinced that Optus Cable Broadband was not as fast as claimed in advertisements, 8 Mb/sec. Maybe I am wrong.
Broadbandguide.com.au has a speed program which on several tests showed my speed to be in the order of about 587 kb/sec.
Peter
The problem is the ISP’s sell their service without mentioning the difference. Especially now that they sell 1.5 megabyte and 6 megabyte speeds and you cannot get near those speeds. Usually they will say something to the effect that it’s the server on the other end that’s slow. If that were the case, then the download would be at the same slow ass speed whether you had a 1.5 meg or a 6 meg connection.
Good, crisp & full of knowledge
This is very important for engineers of ISP.
This document is really very good. I always get confused between Kbps and KBps now its very good.
Thanks for posting such a awesome document.
upper case KBps)means kilo bytes per second which is for storage eg. memory cards. small case kbps) means kilo bits per seconds which is the speed of a connection per second eg. broadband speed of upto 8 mbps (mbps stands for mega bits per second) so it does make sense.
Awesome……….. this article is really helpfull….
thanks
Thank You !
I’m stuck on dial up and this really helps a lot. I’ll stop bitchin’ at the phone company now and lookin’ stupid.
Got to get that satellite installed ! No other options.
Thanx again !
Thank You Very Much !
Now I won’t sound like an idiot when I bi**h at ATT or my ISP.
Got to get that dish installed !
No other options.
Thanx again !
I thought.. i knew every thing about computer before this.. thanks for the information
Really very good article which will clear doubts of every beginner..:)
Awesome dude…. Its a real good article.
its realy a nice article. i appriciate it alot. Thanks
I think the internet providers really take advantage of this confusion, when saying they offer 2MBs, so it’s not just us, it’s them being unfair.
Yes, they did not mention the difference between KBps and kbps. So we’re confused why our internet connection is so slow then. Thank you so much for your info.