Answering the question "Will I have enough to retire?" highlights the impact of taxes and the importance of planning. If you have all your money in tax deferred accounts you will need a lot more because you will need to withdraw 30%, 40% even greater than 50% more to cover the taxes owed on the withdrawal. Pulling money out of a tax free account like a Roth IRA will not generate any taxes. Maximizing your retirement success is directly related to how well you manage the combination of taxable, tax deferred and tax free accounts.