How to determine header image size
 

I figured this out once before but now I'm lost.
How do I determine what size my header photos need to be?
I had them loaded and they were rotating and everything was great. But I realized they were too large and I want to re-size them. Additionally, I'll want to add additional photos over time.
SO.... is there a way I can check certain settings in my system that would then tell me what dimensions to save the photo as (using Easy Crop on my Mac)?
Thanks!
www.oleaustin.com

My rule of thumb is they should be as wide as your 'Layout MAX width' (ATO->Layout MAX width) and as high as your 'Header Image: Height' (ATO->Header Image) unless you have a design that dneeds it otherwise.

I also suggest having the focus of the image agree with your 'Header Image: Alignment' (ATO->Header Image) so it won't vanish if someone resizes the screen.