You can actually calculate password bit strength/safety (assuming the chars are indeed random... and that's a big assumption). A randomly selected character from all printable ASCII characters (roughly 95 chars) has about 6.5 bits of entropy. So an eight character password is about 52-bits strong.

9 = 58.5-bits

10 = 65.0-bits

11 = 71.5-bits

Edit: Spelling & Grammar