Open Question: hello i just wanted to know what is a good weight to be i am 11stones 3 pounds i am 181cm talll(5ft.11) my ide?

hello i just wanted to know what is a good weight to be i am 11stones 3 pounds i am 181cm talll(5ft.11) my ideal is 12 stones...i wanted to know how much pounds is it good to be under your actually ideal weight??? thanks in advance (points will be awarded)