Estimate how pre-tax retirement contributions (401k/IRA) could affect your federal tax estimate.
Tax can feel hard to untangle, especially when income, pre-tax retirement contributions (401k/IRA), the Child Tax Credit and investment gains all interact. Tax Planning helps you explore how further pre-tax retirement contributions may affect your estimated federal income tax.
Free to join. No payment details required.
Guidance, not advice. Tax Planning estimates outcomes based on information entered. It does not replace tax advice, financial advice or retirement planning advice. Tax rules can change. Always verify with the IRS or a qualified CPA before acting.
What you will see inside
Sample data only — your actual results are based on the numbers you enter.
An additional pre-tax retirement contribution may affect more than your retirement account. Depending on your income and circumstances, it may also affect your estimated federal tax liability, the Child Tax Credit phaseout and other income-based thresholds.
When income sits in higher tax brackets, pre-tax retirement contributions can reduce your effective tax rate meaningfully. Understanding where you sit is a useful first step before speaking with a CPA or financial planner.
See how the details you enter may affect an estimated income federal tax estimate for the 2026/27 tax year.
Explore how adjusted net income above $100,000 may reduce your personal allowance, and how pre-tax retirement contributions (401k/IRA) could help restore it.
If you have investment income or are in a higher tax bracket, the tool estimates how pre-tax retirement contributions (401k/IRA) could reduce your federal tax bill.
The tool can give an indication of how pre-tax retirement contributions (401k/IRA) may interact with certain chargeable gains, including top-slicing on investment bonds.
Add wages, self-employment income, retirement income, rental, dividends and savings interest.
Enter any pre-tax retirement contributions (401k/IRA) or Gift Aid already in place this year.
Enter an additional pre-tax 401(k) or IRA contribution to see its estimated effect.
See an estimated before-and-after view of your federal tax estimate, including how 401(k) or IRA contributions affect your taxable income.
This tool estimates your federal tax liability based on the information you enter. The results should not be considered tax advice, financial advice or retirement planning advice. They are designed to help you understand possible areas to discuss with a qualified CPA or to verify directly with the IRS.
Results are based on current understanding of US federal tax law and IRS guidance as at 2026. Tax law can change without notice. The tool does not consider every circumstance that could affect your federal tax estimate, and does not account for state income taxes or FICA.
Always verify figures with a qualified CPA, tax adviser or financial planner before making any retirement contribution, tax or financial decisions.
Tax Relief is included with all 14 Ask Fin tools — free.
Get started — freeFree to join. No payment details required.
Related Ask Fin tools