I am not quite sure but i was wandering the same thing one day and i googled it. There were a lot of helpful websites that have charts to tell you the average weights and if you are under or overweight.
About 1.5 kg
145
110 pounda
6 Foot 1 Inch
125 pounds i think
87 lbs
80kg
check his BMI
80
You would probaly be about 115 pounds
100-155
60