How to make your password strong

Password consists of	Possible combinations	Max, needed time for cracking
5 characters (3 lower case letters, 2 numbers)	365= 60,466,176	60,466,176 / 2,000,000,000 = 0.03 seconds
7 characters (1 upper case letter, 6 lower case letters)	527= 1,028,071,702,528	1,028,071,702,528 / 2,000,000,000 = 514 seconds = approx, 9 minutes
8 characters (4 lower case letters, 2 special characters, 2 numbers)	688= 457,163,239,653,376	457,163,239,653,376 / 2,000,000,000 = 228,581 seconds = approx, 2,6 days
9 characters (2 upper case letters, 3 lower case letters, 2 numbers, 2 special characters)	949= 572,994,802,228,616,704	572,994,802,228,616,704 / 2,000,000,000 = 286,497,401 seconds = approx, 9,1 years
12 characters  (3 upper case letters, 4 lower case letters, 3 special characters, 2 numbers)	9412= 475,920,314,814,253,376,475,136	475,920,314,814,253,376,475,136 / 2,000,000,000 = 237,960,157,407,127 seconds = approx, 7,5 million years