I'm curious as to how the strength of a password is calculated, because the password I just entered wasn't classed at full strength:

![](https://i.stack.imgur.com/vcGB6.png)

When it is full for Google, Medium for Microsoft and Full for another online checker:

![](https://i.stack.imgur.com/PGMuW.png)

![](https://i.stack.imgur.com/71XwZ.png)

![](https://i.stack.imgur.com/QanL2.png)

This is the password:

```
d'c<nKZwSX64

```

(no I'm not using it for anything).

So what is the score based on here?