Good Free 555 Timer Calculator Program?

Thread Starter

NFA Fabrication

Joined Aug 12, 2012
I was using one for the last few years that I really liked, but newer operating systems and other computer changes over the years have made it less and less compatible with anything I own, and I can't find an updated version. It looks like this:

Any suggestions? Looking for one that can be downloaded, so that I can use it offline. Thanks!

Thread Starter

NFA Fabrication

Joined Aug 12, 2012
I just went to Google. Found this one a few days ago that works fine:

I'm using Win7 Pro, but the functioning of the program is independent of that. Why do you seem to want the program to execute on your PC? Why not just use LTSPICE (or similar) if you want a simulator on board?

This is the same one I have been using the past month or so. I was just looking for one that I could download to use offline. I have no idea what LTSPICE is. I am fairly new to electronics. I liked the previous one I had because it allowed me to put in my desired times, and it would then give me the values.


Joined Feb 20, 2011
Here you go. Looks just like the old one, and it's working for me on Windows 8.

EDIT: It is apparently the same one--same version and everything. Don't know why it's not working for you anymore--it's working fine for me.


Last edited:


Joined Jun 8, 2013
I get this error on the PC that I want to use it on when I try to launch the program. Not really sure what it means:

Did you register the .ocx file after installing?

If you installed it in c:\windows\system32\COMCTL32.OCX, then
register it like this:

regsvr32 c:\windows\system32\COMCTL32.OCX<enter>