If you can see your toes, you're not too fat.
If you can see through your toes, you are too skinny.
There is no formula for a healthy height to weight ratio. A lot of other things factor in, such as age, how your body holds and stores fat, and how active you are.
I'm 5'9 and I weight 124, so I guess you're alright.
Approach it from the other direction-Whats the right height for my weight?