I'm trying to estimate support payments for 1 child. 3 years old. I've just about had it with the marriage and am deciding my next move or how much more I can/have to put up with. Are support payments deducted from the gross pay then state and fed taxes determined to equal the net. I've done the numbers both ways and it seems to make a big difference. Thanks. To be simple, I make about 75,000, she makes 41,500. I'm going to see/get as much time with my son as I can. I would prefer custody but from what I've been told that is very unlikely. Roughly how much will my support payments be. Thanks.