Average Rating Calculator
Find a weighted average star rating from rating counts.
Average rating weights each star level by how many people gave it.
How the Math Works
The Average Rating Calculator uses a weighted average formula to determine the overall star rating by accounting for both the value of each star level and the number of ratings at each level. The formula, average = Σ(star × count) ÷ total, multiplies each star rating (1-5) by its corresponding count (number of people who gave that rating), sums all these products, and then divides by the total number of ratings. This method ensures that ratings with higher counts contribute proportionally more to the final average, unlike a simple average which treats all ratings equally regardless of frequency. The result is a more accurate representation of the collective rating sentiment.
Practical Applications
To use this calculator, input the number of ratings for each star level (1 through 5) into the respective fields. For example, if a product received 10 five-star ratings, 5 four-star ratings, and 2 one-star ratings, you would enter these counts into the calculator. It then computes the weighted average by multiplying each star value by its count (e.g., 5×10, 4×5, 1×2), summing those products (50+20+2=72), and dividing by the total number of ratings (10+5+2=17) to get an average of approximately 4.24 stars. This tool is invaluable for e-commerce sites, app store analysis, or any scenario where aggregated user feedback needs quantification.
Day-to-Day Use
In everyday life, this calculator simplifies decision-making when evaluating products, services, or content based on user reviews. Instead of manually averaging ratings or being swayed by a few extreme scores, you can quickly assess the true consensus. For instance, when shopping online, it helps distinguish between products with balanced ratings versus those with polarized feedback. It also aids in comparing options objectively—like choosing a restaurant with consistent 4-star reviews over one with sporadic 5-star and 1-star ratings. By providing a clear, numerical summary, it empowers users to trust their choices and understand collective opinions at a glance.
Worked example
120×5 + 60×4 + 25×3 + 10×2 + 5×1 over 220 → about 4.27★.
FAQ
Why not just count 5-stars?
The weighted average reflects the full distribution of opinions.