Case fans...which size will fit?

[whatthefoc]

O/Cing newbie here with a newbie case cooling question:

I've got a no-name ATX case. Putting together a new P4 system, planning on OCing it.

I see that my case has vents at various positions for additional case fans. My question: How do I know which size will fit my case?

Is see various fans of various sizes (80mm-120mm). Do they have a universal connection, or am I limited by the options provided by my case?

Is it as simple as pulling out the ol metric rule and measuring diameter?

Thanks!!

[Yakbak]

With my generic case, an 80mm fan fit in the vent position fine.

You could get fan adapters, but I'm not sure how thy'd work on your case, space-wise and such.

[Sniperboy]

You can just measure the fan mounts with a ruler. Although, in some cases you might want to cut a bigger hole yourself for more airflow and less noise.

[rogerdugans]

MOST of the cases I've seen have 80mm fans if anything.

Some do have 92mm fans.

I have seen a couple that had spots for 120mm fans from the factory.

I rarelu use the fan placements that the case has anyway: I have a loaded dremel and I am NOT afraid to use it!

Bigger fans mean more airflow with less noise: most of my case fans are 120mm, with some 92s.

About the only time I use 80s is because I can't afford a decently sized case fan, and I have 80s hanging around doing nothing useful; might as well toss them in a case;)