Featured Image Sizig

I am having a hard time getting my featured picture to be the correct size.
What is the correct dimensions I should place on these images.

I have published my draft so you can see what I am talking about.

http://www.ourperfectpalette.com/

Thanks,

Hello @sagunbiade,

Please try to use 640×250px images (or 1280×500px if you want it to look great on retina displays).

Please feel free to ask any other questions that you might have.

Kind Regards, Roman.