I'm 6 foot 1 inch 18 year old male medium built and weigh 176 pounds. What is my ideal weight?

You decide. Ideal weight" charts are based on fallacies. If we believed them, then most triathletes would be "underweight" and most professional football players -- fantastic athletes -- would be "overweight." your ideal weight is whatever looks and feels right to you and enables you to perform your chosen sport (s) best.