I weigh 57kgs and my height is 166, what is my ideal weight?!

Best Answer - Chosen by Voters

anywhere from 130 to 160 is a healthy weight for your age

Depends on what you mean by ideal, BMI wise you're pretty much there(maybe a kilo or 2 under, individually you're probably there though).
Thing is though, up to 70kg's, is well within healthy range, so don't get all hung up on your stats. Especially since sligthtly over has been proven to lead to longer life.