Hi, I have been trying to figure this out but just cannot get my mind around it so I thought I would just ask:

Estimating taxes. I owe SE and income taxes. The SE taxes are based on my gross income minus expenses aka net profit (line 31 from Schedule C, 1040). To calculate income taxes, the base is the AGI. What I don't see/understand is that I would expect my SE taxes to be based on a number from which my income taxes were deducted as well. What don't I see here?