This site that I found is very very useful. I don’t need to say much about it here, because it says it all on the website. Which I hope never goes away.
But – if you are trying to find out what the regulation sizes are for various eBook covers. This is about as much as you need to know.
The site is http://www.ebookcoversize.com/ and in addition, there are some really useful links at the bottom of the page. Especially these ones: Spine Width Calculator | Free Graphic Software | Ebook Cover Designer
That’s it for this post folks. Hope you find it useful.