Estimated Tax Penalty Calculator (Form 2210)
Find out if you owe an IRS underpayment penalty for tax year 2025 or 2024. Check safe harbor, compute quarterly underpayments, and see the interest at the current 7% IRS underpayment rate.
Total tax after credits but before withholding.
W-2 + 1099 withholding (treated as paid evenly).
Used for 100%/110% safe harbor.
If > $150k, safe harbor rises to 110% of prior year tax.
Estimated Payments Made
| Period | Due Date | Required Cum. | Paid Cum. | Underpaid | Days | Penalty |
|---|---|---|---|---|---|---|
| Q1 | 2025-04-15 | $5,000 | $2,500 | $2,500 | 366 | $175.48 |
| Q2 | 2025-06-15 | $10,000 | $5,000 | $5,000 | 305 | $292.47 |
| Q3 | 2025-09-15 | $15,000 | $7,500 | $7,500 | 213 | $306.37 |
| Q4 | 2026-01-15 | $20,000 | $10,000 | $10,000 | 91 | $174.52 |
| Total Penalty | $948.84 | |||||
How the penalty works
The IRS expects income tax to be paid as you earn it. If your withholding plus timely estimated payments falls short of the required installment for any quarter, a non-deductible interest charge accrues on the underpaid balance until the earlier of the date you catch up or April 15 of the following year.
Two simple tests let most taxpayers avoid the penalty entirely:
- De minimis — balance owed after withholding is under $1,000.
- Safe harbor — you paid at least 90% of current year tax or 100% of prior year tax (110% if prior AGI > $150,000).
When neither test is met, Form 2210 breaks the year into four periods. Each period has a required cumulative payment (25% / 50% / 75% / 100% of the required annual amount). Any cumulative shortfall accrues interest at the quarterly IRS underpayment rate until paid.
Frequently asked questions
When do I owe a Form 2210 underpayment penalty?
You generally owe a penalty if your total withholding and timely estimated payments fall short of the smaller of (a) 90% of your current year's tax or (b) 100% of last year's tax (110% if your prior AGI exceeded $150,000). There is no penalty if the balance you owe after withholding is under $1,000.
What is the IRS underpayment interest rate for 2025?
The IRS set the underpayment rate at 8% for Q1 2025 (Rev. Rul. 2024-25) and lowered it to 7% for Q2, Q3, Q4 2025 and Q1 2026 (Rev. Ruls. 2025-7, 2025-11, 2025-18, and 2025-23). The rate is the federal short-term rate plus 3 percentage points.
Does withholding count differently from estimated payments?
Yes. Form 2210 treats withholding as paid evenly across the four installment due dates (Apr 15, Jun 15, Sep 15, Jan 15) by default, even if it was actually withheld only late in the year. Estimated payments only count for the quarter in which they were actually made.
Do I need to file Form 2210 with my return?
For most taxpayers, no — the IRS will calculate the penalty and bill you if one is owed. You must file Form 2210 when you are requesting a waiver, using the annualized income installment method (Schedule AI), treating withholding as paid when it was actually withheld, or in certain joint-to-single filing situations.
Can I reduce the penalty if my income was uneven?
Yes. If your income arrived late in the year (e.g., a year-end capital gain or contractor bonus), you can file Form 2210 Schedule AI to annualize income and shift the required installments later. This calculator uses the simpler regular method; use Schedule AI manually if your income is heavily back-loaded.
Sources
Related insights
Use these guides for rule explanations, planning context, and follow-up questions beyond the calculator result.