For Health Ins.......
Self Employed health Insurance does not go directly on Schedule C so it will not reduce your Net Profit or self employment tax.
If your health ins exceeds your net self-employment income it gets split. An amount equal to your net self-employment income goes on Form 1040 Schedule 1 line 17 (to 1040 line 10) and the remainder gets added in to medical expenses on Schedule A.
You can contribute to a 401K up to the amount of your Net Profit reduced by 1/2 of the SE tax OR to the max contribution allowed for a 401k whichever is Less. It should be on Schedule 1 line 16.
