TurboTax tells you what it calls an "Effective Tax Rate" which is just income tax (Form 1040 line 16) divided by AGI (Form 1040 line 11) and is a relatively useless number when it comes to managing your taxes. What you really care about is your marginal tax rate, the tax rate applied to incremental income. Your marginal tax rate begins with your tax bracket rate but can be affected by side effects such as a change in the taxable amount of Social Security, changes in deductions or changes in tax credits caused by the change in AGI. To figure your marginal tax rate you need to divide the change in tax liability by the change in reported income.
In your case there appear to be no side effects and your marginal tax rate is just your tax bracket rate of 22% plus the 10% early-distribution penalty.
