Screwy Child Support Calculation...?

I got this Child Support Calculator for California somewhere on the web to calculate how my child support would change since my income increased. Turned out I almost have to pay half of my income....! I don't think I'll personally pay that much for our child even if we were still married (since she has other two kids with her previous marriage). I thought the court system was supposively designed to "best interest for the child", is there something wrong with the calculation tool? Or is it just designed to screw up the divorced noncustodial parents?

Sometimes if you make too much money, the judge is allowed to deviate from the schedule. You should talk to a lawyer who can help you fill out the affidavit to your best advantage.