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Ballpark TaxEst. 2026 · Free tools

Estimated tax penalty calculator

The underpayment penalty is interest on what you were short, charged from each quarter's own due date. This shows where you fell behind and what it costs.

Estimated penalty

Not enough detail yet

Enter what you expect to owe this year to see whether you are exposed to an underpayment penalty.

Safe harbour target
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Based on
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Required per quarter
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Total paid in
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Total federal tax you expect to owe this yearIncome tax plus self-employment tax for the whole year.
Total tax on last year's returnUnlocks the prior-year safe harbour, which is often a much lower target.
Last year's adjusted gross incomeAbove $150,000 the prior-year target rises from 100% to 110%.
Federal tax withheld from wages this yearWithholding counts as paid evenly across the year, whenever it actually happened.
Estimated payment made in Q1Due April 15, 2026.
Estimated payment made in Q2Due June 15, 2026.
Estimated payment made in Q3Due September 15, 2026.
Estimated payment made in Q4Due January 15, 2027.
Q1: short by ——
Q2: short by ——
Q3: short by ——
Q4: short by ——
Total penalty—

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Common questions

What is the IRS underpayment penalty rate for 2026?

7% per year for individuals, compounded daily, charged on the amount you were short from each quarterly due date until you pay or until the filing deadline.

How do I avoid the estimated tax penalty?

Pay the lesser of 90% of this year's tax or 100% of last year's — 110% if last year's AGI topped $150,000 — spread across the four quarters. Hit that and no penalty applies however much you end up owing.

Can I fix an early shortfall later in the year?

With withholding, yes: it counts as paid evenly across the year whenever it actually happened, so increasing it in December can repair a January gap. A late estimated payment cannot do the same.

What people use next

Estimates based on published federal rules for tax year 2026. State and local tax is not included. This is general information, not advice about your situation.