Safe harbor
Your estimated annual target
- Estimated 2026 federal income tax
- 90% current-year route
- Estimated safe-harbor target
Why this target:
2026 Federal Tax Planning Tool
Withholding Safe Harbor Check
See whether your projected federal withholding is on track for an underpayment-penalty safe harbor—and the approximate extra W-4 withholding that could close the gap before year-end.
2026Federal
Designed for a quick directional check.
This is not a tax return or penalty calculation. State tax, AMT, credits, capital gains, Additional Medicare Tax, itemized deductions, and special Form 2210 methods are not included in this estimate.
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2026 Federal Withholding Check
Withholding trajectory
Where you appear to be headed
- Federal withholding YTD
- Projected 2026 withholding
- Estimated balance vs. tax
- Estimated safe-harbor shortfall
Year-end remedy
Approximate W-4 Step 4(c) catch-up
Estimated paychecks remaining
FMB planning marker
The planning marker is not an IRS deadline. It is approximately four pay periods before year-end, when a remaining shortfall has to be spread across very few checks.
Supplemental wages
Your 22% withholding gap context
Estimated marginal bracket
Illustrative gap per $100K at 22%
Why withholding can matter late in the year
The timing treatment is different from an estimated payment.
Federal income tax withholding is generally treated as paid evenly across the installment due dates for Form 2210 purposes, even when the withholding occurred later in the year. Estimated tax payments are generally credited when actually paid. That can make remaining payroll withholding unusually useful for a late-year correction, although this tool does not calculate an actual Form 2210 penalty.
Assumptions & limitations
What This Estimate Assumes
- Uses 2026 federal ordinary-income brackets and the basic standard deduction for the filing status entered.
- Treats salary, RSUs and bonus as ordinary wage income for this directional estimate.
- Assumes the 2025 return covered a full 12-month tax year and uses 2025 total tax as entered.
- Uses 100% of prior-year tax, or 110% when the prior-year AGI threshold is exceeded, and compares it with 90% of estimated 2026 tax.
- If you do not enter expected remaining withholding, projected withholding is annualized from YTD withholding using today’s date. RSU/bonus timing can make that projection materially different from reality.
- Does not model state income tax, AMT, capital gains, itemized deductions, tax credits, self-employment income, Additional Medicare Tax reconciliation, spouse 401(k), farming/fishing special rules, or special Form 2210 annualized-income methods.
This is educational planning information, not individualized tax advice. Use the IRS Tax Withholding Estimator or a qualified tax professional for a full household projection.
Primary sources
IRS Publication 15 (2026)
Revenue Procedure 2025-32
IRS Publication 505 (2026)
Instructions for Form 2210
Tax year: 2026 · Plugin rules reviewed against IRS primary sources on August 15, 2026.
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