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 Inflation & Retirement Estimate how much income may be needed at retirement to maintain your standard of living. Put It in a Letter A letter of instruction provides additional and more personal information regarding your estate. Retirement Traps to Avoid Beware of these traps that could upend your retirement.