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Average Rating Calculator

Table of contents

What is the star rating?How to calculate the average rating in a star rating systemWhat is the average five star rating formula?How do I calculate the average 5 star rating?FAQs

The average rating calculator takes a number of votes for each rating (1 star, 2 stars, 3 stars, 4 stars, 5 stars) and gives you the mean rating. This is an example of taking the weighted average, where the number of votes for each category are weighted by their score (i.e., 3 votes for 5 stars have a weight of 15, 6 votes for 4 stars have a weight of 24, etc.).

Keep reading to learn what is the star rating system, the difference between a star classification and an average star rating, and how to calculate the star rating for any combination of votes.

What is the star rating?

The star system is a classification method that uses glyphs and symbols such as stars to visualize in a quick and intuitive way the ranking of many things, from services to purchased items, usually where a certain degree of interaction with the customers is present.

There are two principal types of star classification:

  • Star rating, where a given number of stars is assigned, and the higher the number, the higher the quality. Think of the Michelin star for restaurants or hotel classifications.
  • Star "voting", where many votes expressed as a number of stars are tallied to return a final rating that takes into account the opinion of many people.

We are mostly interested in the latter: in the next section, we will learn how a star rating calculator system works and how to calculate the average rating in such systems. For now, let's explore these systems a bit more!

Assigning an increasing number of symbols to describe the quality of something apparently appeared the first time in guidebooks in the first half of the 19th century (though a monk traveling in Italy in the 12th century already classified a wine as Est! Est!⁠!​ Est!!!). Rather quickly, stars became the preferred symbol. By the beginning of the 20th century, hotels started receiving official star ratings.

With the onset of the internet, it became possible to gather the opinion of many customers in a quick and efficient way, which led to the popularity of average star rating systems. In these systems, the user is tasked with assigning a certain number of stars to a good or service. Once enough votes are gathered, we can show future customers the result: a number of stars that reflects the opinion of the previous customers.

But how do we calculate the average rating in such systems?

How to calculate the average rating in a star rating system

To calculate the average rating in a star rating system, we follow some simple steps:

  1. We count the number of votes for each star number (number of votes for one star, number of votes for two stars, etc.).
  2. We multiply the number of votes by the matching star number: this means that the number of votes for a three-star rating gets multiplied by 3.
  3. We sum all these products.
  4. We divide the result of the previous step by the total number of votes.

This returns a weighted average according to the formula:

 ⁣rating=5×r5+4×r4+3×r3+2×r2+1×r1r5+r4+r3+r2+r1\!\scriptsize \mathrm{rating}\! =\!\frac{5\!\times\! r_5\!+\!4\!\times\! r_4\!+\!3\!\times\! r_3\!+\!2\!\times\! r_2\!+\!1\!\times\! r_1}{r_5+r_4+r_3+r_2+r_1}


  • rating\mathrm{rating}Average rating; and
  • r1r_1, r2r_2, r3r_3, ... — Number of votes for each number of stars.

💡 You may also be interested in our average calculator or in another example of a weighted average problem. Our college GPA calculator is perfect when you want to know what your current grade is or what you need to do to achieve your desired GPA. When calculating this, grades are weighted based on the number of credits.

What is the average five star rating formula?

The formula for the average 5-star rating reads:

average rating = (5r5 + 4r4 + 3r3 + 2r2 + r1) / (r5 + r4 + r3 + r2 + r1)

where ri is the number of i stars responses for i = 1, ..., 5.

How do I calculate the average 5 star rating?

To determine the average 5-star rating, you need to:

  1. Gather the data: write down how many five stars you got, how many four stars, etc.

  2. Add together all numbers from Step 1. This is the total number of responses.

  3. Multiply the number of five stars by 5, the number of four stars by 4, etc.

  4. Add together all numbers from Step 3. This is your total rating.

  5. Divide the number from Step 4 by that from Step 2. This is your average rating!


What is good average five star rating?

The best rating is around 4.2-4.5. Research showed these ratings are the most influential and most trusted. The rating of 5 raises doubts in customers' minds, who think it is "too good to be true".

How do I raise my average rating from 3.5 to 4?

You need to consistently get a rating of at least four stars (so 4 stars or 5 stars). The number of good reviews you need to raise the average depends on how many you've already had. In general, the more bad or average reviews you got in the past, the more good or perfect reviews you need now to raise the average rating.

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