A 401(k) or 403(b) contribution can be an effective retirement tool. As of January 2006, there is a new type of 401(k) or 403(b) - the Roth 401(k) or 403(b). The Roth 401(k) or 403(b) allows you to contribute to your 401(k) or 403(b) account on an after-tax basis - and pay no taxes on qualifying distributions when the money is withdrawn. For some investors, this could prove to be a better option than contributing on a pre-tax basis, where deposits are subject to taxes when the money is withdrawn. Use this calculator to help determine the best option for your retirement.