To understand what a healthy weight is Drs and health practitioners use BMI index
You can find out your BMI by your weight in Kg divided by height in metres squared but there are also calculators online that can help work it out for you.
Normal weight 18.5-24.9
Morbidly obese >40
There are exceptions where you may have a high BMI if you are a sports person like a rugby player for example who has a high muscle mass so you would weigh heavier.