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 Social Security: Maximizing Benefits There are other ways to maximize Social Security benefits, in addition to waiting to claim them. Alternative Investments - Going Mainstream Alternative investments are going mainstream for accredited investors. It’s critical to sort through the complexity. The Facts About Income Tax Millions faithfully file their 1040 forms each April. But some things about federal income taxes may surprise you.