I measured my case fan and i got 100mm... for the cpu fan i got 88mm...
Is there such a thing?
Why exactly are you measuring the CPU fan?
if your looking to replace it, you should probably replace the whole heatsink.
then you just have to work out what socket your CPU is (e.g. LG1155, LG755, LG1366, AM2, AM2+, AM3 etc)