United States · Estimated tax · 2026
Safe harbor estimated tax calculator.
You avoid the underpayment penalty by paying in either 90% of this year's tax or 100% of last year's, and 110% of last year's if your 2025 income was high. This shows the lower of the two in dollars, so you can see how much a surprise year can add without penalty.
With a 2026 tax estimate of $71,253, a 2025 total tax of $42,581 and 2025 AGI of $180,000, the 110% rule applies and the required payment is $46,839 rather than $64,128, about $11,710 per quarter with no withholding. These are the figures from the example in IRS Publication 505.
Your numbers
Your result
How this is calculated
- Current-year rule. 90% of the tax you expect to show on your 2026 return (Pub. 505).
- Prior-year rule. 100% of the total tax on your 2025 return, which must have covered all 12 months. If your 2025 AGI was more than $150,000 ($75,000 if your 2026 filing status is married filing separately), use 110%.
- Required annual payment. The smaller of the two. Withholding and refundable credits count toward it, and what is left is split into four equal installments.
- No payment needed. If you expect to owe less than $1,000 after withholding and refundable credits, estimated tax is not required (Pub. 505, Figure 2-A).
- Due dates for 2026. April 15, June 15 and September 15, 2026, and January 15, 2027. The last can be skipped if you file by January 31, 2027 and pay the balance.
Worked example: Publication 505 figures, single filer, no withholding
| Line | Amount |
|---|---|
| Expected 2026 tax | $71,253 |
| 90% of expected 2026 tax | $64,128 |
| 2025 total tax | $42,581 |
| 2025 AGI | $180,000 (above $150,000) |
| 110% of 2025 tax | $46,839 |
| Required annual payment (smaller) | $46,839 |
| Four equal installments | $11,710 each |
| Left to pay with the 2026 return | $24,414 |
Publication 505 works the same numbers and rounds to $64,128 and $46,839. Choosing the prior-year path means paying $17,289 less before the deadlines than the 90% path would require, with the rest settled when the return is filed.
What this does not cover
- The penalty itself. Use the underpayment penalty calculator if you missed a deadline.
- Farmers and fishers (two-thirds of gross income from farming or fishing), who have a 66 2/3% rule and a single January 15 due date.
- Uneven income. The annualized income installment method can lower early payments; see the linked calculator.
- State estimated tax, a 2025 return that did not cover 12 months, and the section 1062 farmland election.
- Whether your own 2026 estimate is right. The result is only as good as the tax figure you enter.
Method and assumptions
The calculator applies Publication 505 (2026) General Rule and Higher Income Taxpayers rule exactly: required annual payment equals the smaller of 90% of expected 2026 tax or 100% (110% when the AGI test is met) of 2025 total tax. Installments are equal quarters of the shortfall after withholding. If you enter 0 for 2025 tax, Pub. 505 lists "no tax liability for 2025" as a penalty exception when you were a U.S. citizen or resident for all of 2025 and it was a 12-month year, so the tool shows the 90% figure as the cautious amount.
Results vary with your actual income, deductions, credits and filing situation. This page uses the figures you enter and published IRS rules; it does not predict what you will earn or owe. This is general information, not tax, legal or accounting advice; confirm your own situation against the linked IRS instructions or with a qualified preparer. Nothing here collects or stores personal data.
Sources
- IRS Publication 505, Tax Withholding and Estimated Tax (2026), retrieved October 26, 2026
Cite this page: TNAADO Tools, "Safe harbor estimated tax calculator," tools.tnaado.ca/us/safe-harbor-estimated-tax-calculator/, figures retrieved October 2026.
Common mix-ups
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Often assumedPaying in 100% of last year's tax always protects me from the underpayment penalty.
What the source saysPublication 505 raises the prior-year figure to 110% when your 2025 adjusted gross income was more than $150,000, or more than $75,000 if your 2026 filing status is married filing separately. [1]
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Often assumedIf I meet a safe harbor, I will not owe anything when I file my return.
What the source saysPublication 505 defines the required annual payment as the amount you must pay through withholding and estimated tax to avoid a penalty. It is not your full tax, so any tax above what you paid is still due with the return. [1]
Checked against these sources on .
Frequently asked questions
What are the estimated tax safe harbors?
Per Publication 505 you generally avoid the penalty if withholding and estimated payments reach the smaller of 90% of your 2026 tax or 100% of your 2025 tax. The prior-year figure is 110% for higher-income taxpayers.
When does the 110% rule apply?
When your 2025 adjusted gross income was more than $150,000, or more than $75,000 if your 2026 filing status is married filing separately. Farmers and fishers with at least two-thirds of gross income from farming or fishing are excluded from it.
Which 2025 numbers do I use?
Total tax is the amount on Form 1040 or 1040-SR line 24 reduced by the items Publication 505 lists, such as unreported Social Security and Medicare tax from Forms 4137 and 8919. AGI is on line 11b.
Do I need to pay estimated tax if I will owe under $1,000?
No. Publication 505 says you generally need to pay estimated tax only if you expect to owe at least $1,000 for 2026 after subtracting withholding and refundable credits.
Does meeting the safe harbor mean I owe nothing at filing?
No. It only protects you from the underpayment penalty. Any tax above what you paid is still due with your return.
What if my 2025 return did not cover 12 months?
The prior-year safe harbor needs a 12-month 2025 return, so the 90% current-year rule is the one to rely on.
Not tax advice
This is an educational estimate built from the numbers you enter and published IRS rules. It is not tax advice and does not predict what you will earn or owe. To split the payments across a self-employed year, try the quarterly estimated tax calculator.