What image size do I use for the Featured Image?

For our blog and demo site, we use 1750px x 875px for the Featured Image in the blog post header

HubSpot recommends a minimum height of 300px.

The featured image is also used for social media posts and should have a ratio between 2:1 and 300:175 to be best seen on Facebook, LinkedIn, and Twitter (see recommended dimensions for each network).

The POWER blog post template allows you to overwrite the featured image for use on the blog post (the Featured Image on the settings tab will still be used for social sharing).