Quarterly Estimated Tax Calculator (2026)
Self-employed or have untaxed income? The IRS wants tax paid as you earn — in four payments. This tool uses the safe-harbor rule (pay enough of the prior-year or current-year tax and you avoid a penalty) to size each quarterly payment. Estimate only, not tax advice.
| Safe-harbor: 90% of this year | — |
| Safe-harbor: 100% / 110% of last year | — |
| Required annual payment (lower of the two) | — |
| Minus withholding | — |
| Total to pay via estimates | — |
2026 federal estimate using IRS safe-harbor rules. Due dates: Apr 15, Jun 15, Sep 15 (2026) and Jan 15 (2027). Not tax advice.
Quick answer: Take the lower of 90% of your expected current-year tax or 100% of the prior-year tax (110% if the prior-year AGI was over $150,000), subtract any withholding, and divide by four. Paying that amount on time keeps you inside the IRS safe harbor and avoids an underpayment penalty.
How the safe harbor works (2026)
Pay the LOWER of: 90% of this year's tax, or 100% of last year's (110% if last year's AGI > $150,000)
The US tax system is pay-as-you-go. If you have income without withholding — self-employment, investments, rental — you generally must send four estimated payments a year, or face an underpayment penalty. The good news is the safe harbor: hit one of two targets and you are penalty-proof no matter how your actual tax turns out.
- 90% of your current-year tax, or
- 100% of last year's tax — or 110% if your prior-year AGI was over $150,000.
You owe the lower of the two, minus anything already withheld, split into four payments. Basing it on last year's number is safest because it's a known figure — you can't misjudge this year's income and fall short.
When the payments are due
For the 2026 tax year the deadlines are roughly April 15, June 15, September 15 (2026), and January 15 (2027). Note the second "quarter" is only two months and the fourth is four — they are not even. If a date lands on a weekend or holiday it shifts to the next business day.
Important notes
- Withholding counts as paid evenly across the year even if it wasn't, which is why some people bump up W-2 withholding late in the year to cover a shortfall instead of making estimates.
- This estimates the required amount to avoid a penalty — not necessarily your final bill. Reconcile everything on your return.
Estimate the SE portion of your tax with the self-employment tax calculator, and your income-tax side with the tax refund estimator.
Source: IRS estimated-tax safe-harbor rules. Due dates and the $150,000 threshold reflect the 2026 tax year; verify current dates on IRS.gov.
Frequently asked questions
How do I calculate quarterly estimated taxes?
Take the lower of 90% of your expected current-year tax or 100% of the prior-year tax (110% if the prior-year AGI was over $150,000), subtract any withholding, and divide by four. Paying that amount on time keeps you inside the IRS safe harbor and avoids an underpayment penalty.
What is the safe harbor for estimated taxes?
It is a rule that protects you from penalties: if you pay at least 90% of the current-year tax or 100% of the prior year (110% for higher earners), you owe no underpayment penalty even if your actual tax ends up higher.
When are 2026 estimated taxes due?
Roughly April 15, June 15, and September 15 of 2026, and January 15 of 2027. The quarters are not equal lengths, and dates shift to the next business day if they fall on a weekend or holiday. Confirm exact dates on IRS.gov.
Do I have to make estimated payments?
Generally if you expect to owe $1,000 or more when you file and do not have enough withheld, yes. People with a W-2 job can sometimes avoid estimates by increasing their paycheck withholding instead.
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Last updated: 2026-07-11