Macbook Hard Drive Shrinking

My Macbook came with a 250Gb hard drive. Out of all of that i was allowed to around 238 gb. Im assuming the other 12 gb went to the OS and the apps installed. I have not installed anymore apps since then and my hard drive says that is has only 235.85. Its not a big amound of hard drive but i dont know why it keeps getting smaller. Does anyone know why it keeps showing less space every time???

Well whenever you buy a hard drive, the space advertised is never the same as the actual space. For example, I bough a 250GB hard drive and when it had nothing on it, it said it only had 232GB. I also have a 80Gb harddrive that really only has 74GB. I have no clue on why it would go down, I was thinking maybe internet cache or history, but it shouldn't take up 3GB...

After formatting there is always less space left ...

actually, it's not really a formatting issue.. but that's besides the point.. here's 250gb expressed in base 10 (what marketing uses)

mikeMbp:~ mike$ df -H
Filesystem Size Used Avail Capacity Mounted on
/dev/disk0s2 250G 145G 105G 59% /


here it is in base 2, which is what OS's historically use
mikeMbp:~ mike$ df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/disk0s2 233Gi 135Gi 98Gi 59% /


the GUI on snow leopard shows it as...
249.72 GB

unless literal by k
mikeMbp:~ mike$ df -k
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/disk0s2 243862672 141307124 102299548 59% /

but that's not quite right either

So I'm really unsure how the GUI calculates it. The differences in mathematical expression have been covered ad naseum and if you really want to understand that search, or hit google.. there's a ton of good info out there. Why are you using more and more drivespace? Are you saving things? Are you downloading things (check downloads, I bet you are)? Are you just utilizing more cache and temp files (probably are too).. you don't just use hard drive space by installing apps.

Shrinking? I told you not to get it wet!

If you're in California, it may be the new 10% HD tax imposed by the State Legislature.