If the side business is profitable (and makes enough to enact this plan), it works like this for a solo 401(k): the employee's contribution (you) up to $18,000 and a profit sharing contribution up to 25% of the business earnings. For 2017, it maxes out at $54,000 if you're under 50 years old.
Keep in mind though that maximums are per person not per company; if you keep the day job 401(k) (and potential match) you'd have to reduce the contributions from your side business to not exceed the maximum.
Keep in mind though that maximums are per person not per company; if you keep the day job 401(k) (and potential match) you'd have to reduce the contributions from your side business to not exceed the maximum.
https://www.irs.gov/retirement-plans/one-participant-401k-pl... https://scs.fidelity.com/products/mobile/sepMobile.shtml