Sometimes the features have completely different scales. For example lets imagine a website displaying a list of movies. Each movie has a **score** between 0 – 10 and also displays the **number of likes**, that represents how many people has clicked on the button “I like the movie”. We cannot calculate an average of these two features because they have completely different scales.

### Scaling formula

To solve this problem we can scale both features to values between 0 and 1 using the following formula:

### Practical example

We have the movie “Ex machina” with the following features:

**Score**: 8**Number of likes**: 300,000

Given that the maximum number of likes is 600,000, which is the scaled value of both values combined?

#### Calculate the scaled score

We apply the formula to the Score:

#### Calculate the scaled number of likes

Now we apply the formula to the number of likes:

Finally we have the features within the same scale:

- scaled score =
**0.8** - scaled number of likes =
**0.5**

So now we can calculate the average normally. Note that this would only make sense when we are comparing features that are somehow related.