Kindle cover image

Question

I was wondering about the book cover image used for KDP. Amazon documentation only mentions the minimum required resolution of the pictures. So, I assume:

1. I should upload the best quality picture that I have available
2. Amazon themselves will handle downsampling depending on the device requesting a download
3. The cover image size is NOT included in the book size used to determine delivery fees

Can anyone confirm whether my understanding is correct?

Answer 1

The Kindle Direct Publishing guidelines for ebook creation states that:

1. Cover image should ideally have 8:5 aspect ratio (height/width).
2. Minimum 625px for short side and 1000 for long. Ideally 2500px for long.
3. Cover size cannot exceed 50 MB.
4. It is recommended to turn off compression.
5. DPI for image should be 72.
6. Color mode of image should be RGB.

There are more details in the link above, but those 6 points sum it up pretty well.

To be more specific on your questions:

1. Yes, you should upload the highest quality image you have, but it is important to adhere to those guidelines above.
2. The cover in mobi will never be modified by amazon unless it is absent. Device itself will scale it down or up.
3. I'm not sure about that one.

Answer 2

Re 3: "... the size of your cover image won’t affect the size of the delivered ebook…usually.

In some cases (usually due to an incorrectly formatted interior file), KDP will fail to correctly identify the cover, and will instead add a duplicate cover image. This is costly, as you’re padding the ebook with an unnecessary and unoptimized copy of your cover."

More here: https://selfpublishingadvice.org/are-you-losing-money-on-kdp-delivery-fees/