Quarterly Estimated Tax Calculator
2026 estimated payments with the safe harbor rule.
Filing status
Include 20% QBI deduction?
Simplified. Limits apply at higher incomes and for some service businesses.
Line 24 of your 2025 Form 1040. Enter 0 if you had no tax liability.
Last year's AGI over $150,000?
Your result
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Enter your numbers to see the result.
This quarterly estimated tax calculator estimates your 2026 federal tax, including income tax and self-employment tax, then applies the IRS safe harbor rule to find the smallest required annual payment. It subtracts any withholding and splits the rest into four payments with their due dates, so you can avoid an underpayment penalty.
What is a Quarterly Estimated Tax Calculator?
The US tax system is pay-as-you-go. Employees pay through withholding, but if you are self-employed, earn investment income or have a side business, you usually need to make estimated tax payments four times a year using Form 1040-ES. Paying too little during the year can lead to an underpayment penalty.
The safe harbor rule protects you from the penalty if you pay at least the smaller of 90% of this year’s tax or 100% of last year’s tax (110% if last year’s adjusted gross income was over $150,000). This quarterly estimated tax calculator estimates both amounts and shows the four payments.
How does the Quarterly Estimated Tax Calculator work?
The calculator estimates self-employment tax on 92.35% of your profit, subtracts half of it from income, takes the 2026 standard deduction and an optional simplified 20% qualified business income (QBI) deduction, and applies the 2026 tax brackets. Total tax is income tax minus credits plus SE tax. The required annual payment is the smaller of 90% of that total and 100% or 110% of last year’s tax; withholding is subtracted and the rest is split into four equal payments.
How to use the Quarterly Estimated Tax Calculator step by step
- Choose your filing status.
- Enter your expected net self-employment profit and any other income.
- Enter withholding and credits.
- Enter last year’s total tax and whether your AGI was over $150,000.
- Read the quarterly amount and due dates.
- Pay through IRS Direct Pay or your online account, and update the estimate mid-year.
Quarterly Estimated Tax Calculator example with real numbers
Alex is a self-employed consultant filing single. He expects $90,000 of net profit in 2026, has no withholding, and his total tax on his 2025 return was $14,000.
| Example input | Value |
|---|---|
| Filing status | Single |
| Net self-employment profit | $90,000 |
| Other income (W-2 wages, interest) | $0 |
| Federal tax already withheld this year | $0 |
| Tax credits (e.g. child tax credit) | $0 |
| Include 20% QBI deduction? | Yes |
| Total tax on last year's return | $14,000 |
| Last year's AGI over $150,000? | No |
| Example output | Value |
|---|---|
| Each quarterly payment | $3,500 |
| Estimated 2026 total tax | $19,316 |
| Income tax | $6,599 |
| Self-employment tax | $12,717 |
| QBI deduction used | $13,508 |
| 90% of this year's tax | $17,384 |
| 100% of last year's tax | $14,000 |
| Required annual payment (safe harbor) | $14,000 |
| Balance due at filing if you pay this | $5,316 |
The quarterly estimated tax calculator estimates his 2026 total tax at $19,316. Under the safe harbor rule he needs to pay $14,000 during the year, which is $3,500 each quarter.
Key features of this Quarterly Estimated Tax Calculator
- Income tax and SE tax together
- 2026 brackets and standard deduction
- Safe harbor 100% and 110%
- Withholding and credits
- Due-date schedule
Who should use the Quarterly Estimated Tax Calculator?
Who is this Quarterly Estimated Tax Calculator for?
- Freelancers and 1099 contractors
- Small business owners
- Landlords and investors
- Employees with large side income
Practical use cases
- Setting quarterly payments
- Avoiding the underpayment penalty
- Checking whether to raise W-2 withholding instead
- Re-estimating after a big contract
Key benefits
- Penalty-focused: safe harbor built in.
- Complete: SE tax included.
- Clear: four payments with dates.
- Private: runs in your browser.
Tips for better results
- Paying 100% (or 110%) of last year’s tax is the simplest way to avoid a penalty if income is rising.
- If income is uneven, the annualized installment method on Form 2210 may lower early payments.
- Raising W-2 withholding counts as if paid evenly through the year.
- Make state estimated payments too, if your state has income tax.
Common mistakes to avoid
- Forgetting SE tax when estimating.
- Missing the January payment for the prior year.
- Using the 100% rule when last year’s AGI was over $150,000.
- Paying the full amount only at filing time.
Limitations of this Quarterly Estimated Tax Calculator
- The QBI deduction is simplified; limits apply at higher incomes.
- Capital gains, itemized deductions and other taxes are not included.
- State tax is not calculated.
Quarterly Estimated Tax Calculator vs other ways to calculate
| Option | How it avoids the penalty |
|---|---|
| 90% of this year’s tax | Pay most of what you will owe |
| 100% of last year’s tax | Safe if last year’s AGI was $150,000 or less |
| 110% of last year’s tax | Needed if last year’s AGI was over $150,000 |
| Owe under $1,000 | No estimated payments required |
For SE tax alone, use the self-employment tax calculator. For a full income tax estimate, see the US income tax calculator.
Privacy and data handling
This Quarterly Estimated Tax Calculator runs entirely in your browser. The numbers you type are not sent to Qorico or stored on any server, and nothing is saved after you close the page. The Copy and Download buttons create the result on your own device. If the page has analytics turned on, it may count that a calculation happened, but it does not record the values you entered.
Quarterly Estimated Tax Calculator FAQs
When are 2026 estimated tax payments due?
15 April 2026, 15 June 2026, 15 September 2026 and 15 January 2027, moved to the next business day if needed.
Who needs to pay quarterly estimated taxes?
Generally anyone who expects to owe $1,000 or more after withholding and credits.
What is the safe harbor rule?
You avoid the penalty if you pay the smaller of 90% of this year’s tax or 100% of last year’s (110% if last year’s AGI was over $150,000).
How do I pay estimated taxes?
Online through IRS Direct Pay, EFTPS or your IRS online account, or by mail with Form 1040-ES vouchers.
What if I miss a payment?
Pay as soon as you can; the penalty is interest-like and grows with time.
Do I include self-employment tax?
Yes. Estimated payments cover income tax and SE tax together.
Related tools
Sources and references
We checked the method and the current figures used in this Quarterly Estimated Tax Calculator against these official and primary sources:
Written and reviewed by the Qorico Team
