When customers review a product, the default ratings are quality, price, and value. In addition to these, you can add your own custom ratings. The five-star ratings that appear on catalog pages are averaged for each product.
Create your own ratings
On the Admin sidebar, go to Stores > Attributes > Rating.
In the upper-right corner, click Add New Rating.
In the Rating Title section, enter the Default Value for the new rating.
If applicable, also enter the translation for each store view.
In the Rating Visibility section, set Visibility In to the store view where the rating is to be used.
To select multiple store views, hold down the Ctrl key (PC) or the Command key (Mac) and click each item.
Ratings are not visible unless assigned to a store view.
For Sort Order, enter a number to determine the order of this rating when listed with others.
If you want to show your rating on the storefront, select the Is Active checkbox.
When complete, click Save Rating.
The average rating for all reviews is displayed for each product on the catalog product grid page.