Hi folks, this is a really interesting online service !
Thanks to The Password Meter you can test your own passwords understanding how much safe they are.
As you may see from the previous picture, this smart tool uses a deduction process to evaluate your password strength, for instance if you put only letters on your password, it will reach a very weak score due to the -n rule. The deduction process is useful to subtract points to the total score while the additions process adds score to it. Both follow a well known rate putted into Rate column. Moreover if you scroll down you can download the entire package, All that is still free !