Want To Define Custom Size For Images

Hello, Everyone,

I am trying to resize images for the posts but i am unable to find a solution for it.

I want to change the WordPress default medium size images: It’s 237 X 216 But I want something like this: 300 X 280. Is that possible to change these default setting for images?

Link to the post — https://www.reviewwind.com/best-recliner-power-lift-chairs/

The present medium size images look very small. I am trying to figure out how I can do this without losing the image quality too.