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. Have A Question About This Topic? Name Email Address Question Thank you! Oops! Related Content Fixed or Variable Mortgage, Which Should You Pick? When selecting a mortgage, one of the most critical choices is between a fixed or variable interest-rate mortgage. Social Security Taxes Estimate how much of your Social Security benefit may be considered taxable. Lifetime of Earnings Estimate how much you have the potential to earn during your working years.