# How much space should I expect to "lose" on a new 160GB HDD?
**URL:** https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610
**Category:** Factual Questions
**Created:** [January 25, 2005, 5:09pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610 "2005-01-25T17:09:35Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@RumMunkey](https://boards.straightdope.com/u/RumMunkey)
#### Post date: [January 25, 2005, 5:09pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610/1 "2005-01-25T17:09:35Z")
OK, first off, this is \*\*not \*\*the 137 GB Windows limit issue. My bios isn’t very old either, but I am looking for an update while this posts.
I installed a 160 GB hard drive, but windows shows considerably less space available on that drive.
I know to expect _some_ space to be “lost” because of the way manufacturers represent disk space in their marketing (the 1000 MB Gig).
My question is, how much of a difference should I expect between a drive advertised as being 160GB, and the actual available space (when used as secondary storage -no o/s.)?
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### Author:  [@Nunavut\_Boy](https://boards.straightdope.com/u/Nunavut_Boy)
#### Post date: [January 25, 2005, 5:24pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610/2 "2005-01-25T17:24:18Z")
My 160GB shows up in windows as 149GB.
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### Author:  [@bouv](https://boards.straightdope.com/u/bouv)
#### Post date: [January 25, 2005, 5:26pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610/3 "2005-01-25T17:26:13Z")
The problem arises in decimal vs. binary notation. They like to say there is 160 GB, and to them, 1 GB = 1,000,000,000 bytes (10^9.) In actuality, a GB is 2^30 power, or 1,073,741,824 bytes.
If we divide 16_10^9 by 16_2^30, we get 0.93, a 7% loss of space. So in reality you have about 149 GB.
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### Author:  [@RumMunkey](https://boards.straightdope.com/u/RumMunkey)
#### Post date: [January 25, 2005, 5:29pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610/4 "2005-01-25T17:29:09Z")
Crap.
That’s exactly what I got. Oh well, the good news is I installed the drive correctly and have no bios issues.
The bad news is I pine for those 11 Gigs… ☹
Thanks folks.
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### Author:  [@bouv](https://boards.straightdope.com/u/bouv)
#### Post date: [January 25, 2005, 5:29pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610/5 "2005-01-25T17:29:46Z")
Oh, not to hijack this too much, but my IBM hard drive shows up as 123 GB. Can someone expplain this? (And it was marketed as a 120 GB hard drive, which would make me think there was 111 GB, but somehow I got 3 more.) And it’s not jsut 120\*2^30 either, because that nets me with 128 GB. 😕
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### Author:  [@Padeye](https://boards.straightdope.com/u/Padeye)
#### Post date: [January 25, 2005, 5:59pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610/6 "2005-01-25T17:59:12Z")
As my father is fond of saying, “some people would bitch if you hanged them with a new rope.” Criminy, you get an extra 3x2^28 bytes for free. I remember when we struggled to have enough kilobytes 😃 Yeah, yeah, I realize you were not complaining I just had to go in old coot mode for a minute there.
I think IBM just took the more ethical route used the number of true gigabytes then rounded it[down] to the nearest round number rather than calling 10^9 a gigabyte in labelling their drive.
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### Author:  [@Skywatcher](https://boards.straightdope.com/u/Skywatcher)
#### Post date: [January 25, 2005, 8:49pm UTC](https://boards.straightdope.com/t/how-much-space-should-i-expect-to-lose-on-a-new-160gb-hdd/286610/7 "2005-01-25T20:49:20Z")
> [@Padeye](#):
>
> I think IBM just took the more ethical route used the number of true gigabytes then rounded it[down] to the nearest round number rather than calling 10^9 a gigabyte in labelling their drive.
I’ll go along with that, having been the proud owner of a 40 (43) gig IBM drive