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 How Big is Money? Learn a little about worldwide currency in this fun infographic Federal Income Tax Use this calculator to estimate your income tax liability along with average and marginal tax rates. A Penny Saved is Two Pennies Earned Here are some simple and inexpensive energy-saving tips that may help you save money.