Divorce Settlements and maintenance?

I have recently left my wife and my eldest child of 16 and in full time education is with me however my wife remains in the family home with my 2 younger children. Has anybody any ideas as to the monies I will have to pay out to my ex wife ? I earn 30k p.a and continue to pay the mortgage on the family home of 600 PCM any ideas ? ( oh and so far it’s all amicable fingers crossed)