IMDb Rating System

What are IMDb ratings?

The IMDb rating system is a way for moviegoers to rate the shows and movies that they watch on a scale of 1to 10. Anyone who is registered on IMDb can vote on a movie – for more info on how to sign up with IMDb, check out our How to Sign Up for IMDb tutorial

How the Rating System Works

Since you have to be registered on the site to vote, IMDb can keep track of the users who vote on everything (though they don’t make this information public) and thus it allows you to vote as many times as you like on one thing – but your most current vote will rewrite your previous vote.

Most ratings use what is known as the arithmetic mean, which means all votes are treated equally and the rating is found by adding up the sum of all votes and dividing equally. So if there were two votes – a vote for one and a vote for nine – then the rating would be a five. 

IMDb uses what is known as weighted average, which means that different votes hold a different weight – though IMDb won’t divulge exactly how their method works, they ensure it is fair and used across the site for all shows and movies. An example of a weighted average would be a hotel room. If there were five categories and it scored high in four, it could still get a low rating. If it was cost-efficient and well-located, but was infested with cockroaches, then the cleanliness category would carry more weight than the others.

How to Rate a Movie

It’s really simple to rate a movie on IMDb. All you need to do is be logged in, and you can rate whatever you like. 

  1. First you need to find the movie you want to rate. To do this, type in the movie or show title after clicking on the search bar at the top. Sometimes by typing in the first few letters, you’ll see what you’re looking for in the drop down menu. Once you’ve found it, click on it. If it doesn’t appear there, select See all results for [insert search here]

  2. This will show you movie and TV show titles that match what you searched, along with the names of actors or fictional characters that match. However, if you only put in the first few letters and want to do a full search like this, you’ll only get results that match those letters. In the search bar, IMDb tries to guess what you’re typing, which is why you may only need to type in a few letters. See the difference in search results from the screenshot above and below, both using the letters “casa.” 

    Find the title you’re looking for and click it. If you still can’t find what you’re looking for, try reading our IMDB Advanced Search tutorial

  3. You’ll be taken to the movie’s page. From there, you’ll notice a section for ratings to the right of the movie poster. The large star with the number in it shows the rating it has right now.  For this example, we’ll use Casablanca (1942), which has a rating of 8.6 out of 10. 

  4. Next to it are 10 stars, which will be grey if you haven’t already rated this title.  Let’s give this movie a nine out of 10. Click on the ninth star from the left, and you’ll notice the first nine stars will turn purple. 

You’ll be able to see your rating each time you come to the title’s IMDb page – which can be helpful for yourself if you want to re-watch a movie, you’ll know which movies you didn’t particularly like and which ones you loved.  You can also change your rating in the same way that you made your first one, if your opinion on a show or movie changes.