We simply convert each individual review’s rating of that product to a score out of 100, add together the scores from all the reviews, and then divide that total by the total number of reviews. For example, were one review to have rated the product 4.5 stars out of five, we would convert that to 90; and were the next review to have given a rating of 7 out of ten, we would convert that to 70. Then we would add 90 and 70 together and divide the total of 160 by two (the number of reviews) to give the ReviewsReviewed composite rating of 80.

It’s worth remembering though that some reviews are more authoritative than others. Sadly we have yet to devise an algorithm that will precisely weight the importance that should be accorded to each review. So our composite ratings cannot really be considered definitive. They are a guide. Nothing more.