power supply dimension standard?

[HomeSA]

Is there a physical dimension standard for various power supply types; for example, ATX, BTX, MicroATX, and many other designations that I see on the net?

I have the hardest time figuring out what will fit a case when looking to order a power supply. I have been lucky twice so far by just eyeballing the pics on the newegg site, but there has to be a better way.

Right now I am trying to figure out what would be a replacement PSU for HP Pavilion 8668c and don't know where to start?

Any pointers would be appreciated.

-HomeSA

[mjc]

Chances are that the HP is not going take a full size ATX PSU...probably a micro.

But other than the general sizes, no, I don't think they are all that standard.

[schusterjo]

HP takes a certain type of PS
Here is a website that would have a power supply for a HP,Dell ext..
has a nice cross reference tool as well
www.atxpowersupplies.com