How to deduct Solo 401k contributions
The answer depends on whether you offer to match your employees' retirement contributions. If you don't offer an employee match, you need to report your contributions to the solo 401(k) on the 1040, not the Schedule C. Report any amounts you put into the 401(k) on line 28 of form 1040, where it says "Self-employed SEP, SIMPLE, and qualified plans.
If you do offer your employees a 401(k) matching contribution, then report that information on the Schedule C, under the pension line 19, he says.
FICA needs to be paid on entire income-
SE taxes
Put on ScheduleC to avoid SE taxes
Dividends paid to S-Corp don't need to pay SE taxes. But can S-corp have Solo 401K?
Todo: tax sheltered businesses
Calculate amounts: http://www.sepiracalculator.com/