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 When Do You Need a Will? When do you need a will? The answer is easy: Right Now. Lifetime of Earnings Estimate how much you have the potential to earn during your working years. My Retirement Savings Estimate how long your retirement savings may last using various monthly cash flow rates.