Deductions & credits

No.  Net Income is AFTER expenses on schedule C.  The SE tax is on your Net Profit of $400 or more.  

 

See Schedule C,  https://www.irs.gov/pub/irs-pdf/f1040sc.pdf 

 

And Schedule SE for tax https://www.irs.gov/pub/irs-pdf/f1040sse.pdf