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 Message Thank you! Oops! Related Content Comparing Mortgage Terms Estimate the total cost in today's dollars of various mortgage alternatives. Capital Gains Tax Estimator Use this calculator to estimate your capital gains tax. Social Security Taxes Estimate how much of your Social Security benefit may be considered taxable.