Self-Employed Retirement Plans Estimate the maximum contribution amount for a Self-Employed 401(k), SIMPLE IRA, or SEP. You are viewing this website at a small screen resolution which doesn't support calculators. Click here to view this calculator. Related Content Net Unrealized Appreciation (NUA) Explained Have you considered the special tax treatment on company stock held in a 401(k) plan? IRA Withdrawals that Escape the 10% Tax Penalty The list of IRA withdrawals that may be taken without incurring a 10% early penalty has grown. A Primer on Dividends A company's profits can be reinvested or paid out to the company’s shareholders as “dividends."