Business rating for Google is calculated by taking the average of all scores and showing that rating.

So, if you’ve got 26 ratings, you’d add up all-stars earned for all 26 studies and divide the total number of stars by 26 (the number of reviews), which would give you your Google ranking.

Example: There are 24 5-star ratings, one of which is a 2-star review, the other a 4-star review. This is 126 total Google stars.  Then you split the 26 studies into 126 leads, and your average review rating is 4.8.

Examples of What the Google Rating looks like in search results: