Hi ciaran. I will look up my book for you.
At 6 feet tall you are 183cm
You5 healthy weight range is 68-85kg or 10stone 10 pounds - 13 stone 8 pounds
I think there are 14 or 16 pounds in a stone - can't remember which it is exactly. You do the calculation.
You BMI to be healthy should be less than 25
You can get calulators on the web to work that out.
At the top of the healthy weight range, you may still look and feel a little flabby. At the bottom, you will be very lean but still look good. Aim for the middle to look your best but not skinny.