Product Image is the first impression and the closest thing for customers to picture the products in their mind. Therefore, it is really important not only to use high-quality images to describe the product but also to keep your site in good performance.
Magento image sizes configuration
- In your Magento backend, go to System > Configuration. On the left menu under Catalog, select Catalog.
- Expand the Product Image section, and do the following:
a. In the Base Image Width field, enter the maximum width that the base image is to be rendered.
b. In the Small Image Width field, enter the maximum width that the small image is to be rendered.
- When complete, click Save Config.
Magento image types
Based on different types of images, product image in Magento website is divided into 3 main Sizes:
Thumbnail images appear in the thumbnail gallery, shopping cart, and in some blocks such as Related Items. Example size:
50 x 50 pixels
- Small Image
The small image is used for the product images in listings on category and search results pages, and to display the product images needed for sections such as for Up-sells, Cross-sells, and the New Products List. Example size:
370 x 370 pixels
- Base Image
The base image is the main image on the product detail page. Image zoom is activated if you upload an image that is larger image than the image container. Example sizes:
470 x 470 pixels (without Zoom)
1100 x 1100 pixels (with Zoom)
See also: How to Resize Images in Magento 1 & 2