When you upload an image on your site, the image will automatically be cropped according to the thumbnail sizes defined in the theme.

The thumbnail sizes that are defined in the theme are as follow:

• 888 x 500 – Used in banner/slider and news widgets.
• 800 x 450 – Used in news widgets.
• 720 x 540 – Used in news widgets.
• 450 x 600 – Used in news widgets.

Note: If you have switched themes, then use Regenerate Thumbnails, plugin to regenerate thumbnails.