Amazon says it does not use a simple average to calculate overall star ratings. Amazon describes star ratings as model-based and says factors can include how recent the review is, whether the customer bought the item on Amazon, and signals related to feedback authenticity.
That matters for teams planning launch traffic, ads, coupons, or deals because the visible rating is not just a static average. It is part of the listing’s commercial readiness picture.
Does Amazon say overall star ratings are just an average of review scores?
No. Amazon says in the Reviews from Amazon FAQ that it does not use a simple average to calculate the overall star rating and percentage breakdown by star.
That matters because it means the visible rating is not just arithmetic. Amazon is applying a weighting or ranking model rather than displaying a raw average.
What factors does Amazon say it considers?
In the same Amazon-owned FAQ, Amazon says factors include:
- how recent a review is
- whether the reviewer bought the item on Amazon
Amazon’s customer reviews and star ratings explainer says Amazon uses advanced models rather than a simple average and names recency, purchase context, and authenticity as factors that influence star ratings.
Do recent reviews count more in overall star rating calculations?
Amazon says review recency is one factor it considers, but it does not publish the exact weighting formula.
So the careful answer is yes, Amazon says recency can matter. It does not say exactly how much more a recent review counts compared with an older review.
Does Amazon explain the full weighting formula?
Not publicly. Amazon gives examples of factors it considers, but it does not publish a complete formula or exact weights in the sources above.
So the safest summary is that Amazon discloses direction, not the full math.
Why does this matter for retail readiness?
Teams often treat a rating as a single number, but Amazon’s wording points to a broader readiness question. A listing that is about to receive more traffic should be evaluated for:
- recent customer feedback
- purchase-context signals
- product-page clarity
- rating-threshold pressure before coupons, deals, ads, or events
That is why rating calculation belongs next to promotion readiness and retail readiness, not just review reporting.
If this question is part of a launch, rating threshold, recency, or promotion plan, Standwell’s Programs page explains how managed readiness work fits.