Consider the tax implications Contributions to a Traditional 401(k) plan are made on a pre-tax basis, resulting in a lower tax bill and more take home pay. Contributions to a Roth 401(k) are made after taxes, which means taxes are paid on the amount contributed in the current year. The reverse is true once you are eligible to make 401(k) withdrawals. Withdrawals from Traditional 401(k) plans are taxable, while those made from a Roth 401(k) are not. Use this calculator to figure out which option is best for you today and in the future.