Images that aren’t properly optimized to meet Facebook’s image sizing are a needlessly common occurrence that can tarnish an otherwise stellar Facebook page or post.

In this post we aim to give you the knowledge you need to not only post images that are appropriately sized for every Facebook image type, but also to ensure that the images you post are of the highest quality (including what size images to use in your Gleam campaigns).

The profile image is a square image that gets resized to 170 x 170px on desktop and 128 x 128px on mobile devices.

This is twice as large as profile images are displayed on desktop.

For a business page, the cover photo will be resized to 828 x 315px on desktop and 640 x 360px on mobile devices.

The image will be adjusted to varying sizes when it appears on mobile devices or news feeds.

The text above is a summary, you can read full article here.