Hi I would like to know the calculation so I can work out data transfer rates on my lan.

I have found online calculators that do the job but I would like to know how they do it!

Any advice is welcome.

Thanks

brian

An example would be:

"It takes 1 minute to download a 7.5 MB data file. At what bit rate is the data being transferred?"

7.5MB / 60seconds = 125KB per second

125KB per second * 16 ( bits per word ) = 2Mb per second

Edited November 19, 200718 yr by RJM

Hi RJM, thanks for the reply. I seem to have come with a different figure form you.

Can anyone confirm what it right?

Thanks

7.5Mb = 7,500Kb = 7,500,000 bytes = (7,500,000 x 8 bits = 60 million bits. Divide that by sixty seconds in a minute and you get a data rate of 1 million bits per second or 1Mbps.

Hi RJM, thanks for the reply. I seem to have come with a different figure form you.

Can anyone confirm what it right?

Thanks

7.5Mb = 7,500Kb = 7,500,000 bytes = (7,500,000 x 8 bits = 60 million bits. Divide that by sixty seconds in a minute and you get a data rate of 1 million bits per second or 1Mbps.

i'm pretty sure you are right. for some reason RJM multiplied by 16 which should have been 8, at least as far as i know it should have been 8

Actually, 7.5MB = 7,864,320 bytes.

Try out Converber, it may help you a lot brian.

Hi guys thanks for this.

TARUM: I still get 7,500,000 bytes when using that utility. Thanks for that by-the-way. Can you show me how your doing the calculation?

Thanks

Yup, I messed up. There are 16 bits per word ( which I mentioned ) but only 8 bits per byte. I should have multiplied by 8 bits per byte instead of

16 bits per word.

The correct rate is 1Mb/sec

Edited November 20, 200718 yr by RJM

Brian- Ok here is how you calculate that

1024 bytes = 1KB

1024 KB = 1 MB

1024 MB = 1GB

etc

the reason for 1024 is to do with information being stored in binary (in bits). 1024 is 2^10.

Therefore 7.5MB = 7.5 * 1024 *1024 = 7864320 bytes

This makes your calculation into

7864320 / 60 = 131072 bytes per second, * 8 bits = 1048576 bits per sec, = 1024 Kb/s or 1Mb/s

Just so you know some manufacturers of hard drives have been fined in Europe for advertising a hard drives as having more space because they use the wrong conversion e.g. 500GB, they use 1000 bytes = 1Kb etc, so they are actually selling 465GB of space ((500*1000*1000*1000 )/ (1024*1024*1024))

This is also why in Windows when you look at a hard drives space info it will say one figure for bytes and something different for GB, e.g. 4,550,839,296 bytes used (4.23GB used)

Edited November 20, 200718 yr by phkninja

Thanks guys !

I think I have found out what I need....

Thanks again for taking to the time to answer.