The normal weight range for a 170cm male is 53.5kg to 69.4kg, and the optimal weight, or standard weight, is 63kg. Clinically, the common methods of evaluating body size include calculating the BMI index and calculating the standard weight. 1. BMI BMI index = weight (kg)/height (m) square, BMI index in 18.5 ~ 23.9 belongs to the normal range, below 18.5 is thin, 24 ~ 27.9 for overweight, more than 28 is obese. For a male with a height of 170 cm, weight (kg) = BMI * height (m) squared. Normal weight range is (18.5*1.7*1.7)=53.465kg～(24*1.7*1.7)=69.36kg. 2. Standard Weight Standard weight (male) = (height cm-100)x0.9(kg), standard weight (female) = (height cm-100)x0.9(kg)-2.5(kg). Standard weight up and down within 10% is normal, more than 10% to 20% is overweight, 20% to 30% for mild obesity, 30% to 50% for moderate obesity, more than 50% for severe obesity. For a male with a height of 170 centimeters, the standard weight = (170-100)*0.9=63 kg. The normal range is (63*0.9)=56.7 kg to (63*1.1)=69.3 kg. If you are underweight or overweight, you should go to the hospital in time to improve the relevant examination, so as not to miss the condition.