How to Change the Default Image Sizes in the WordPress Dashboard
When writing a post or a page, you’ll find that the default image sizes are 150px square for thumbnails, max width of 300px for medium-sized images, and a max width of 1024px for large images. Ever thought about changing these to be a little more flexible to your needs?
The good news is that you can change the default image sizes directly through the dashboard. Go to Settings >> Media and input new values for the sizes:
There’s no need to hunt for a plugin to do this for you – you’ve got it right at your fingertips in the WordPress dashboard!