Selecting the Products Thumbnail Size
Choosing the Thumbnail size for Products, using the Theme Options interface.
Written by RockyThemesTo select the thumbnail size for Products, for Category and Archive pages navigate to Theme Options -> WooCommerce -> Products Thumbnail Size
Choose either Full Image or Theme Generated.
The Theme Generated will create cropped image versions from the original images at the following size: 300×400 px. This means that each image set as the Featured Image for your products have to be at least 300×400 (width x height) otherwise the image will not be correctly created.