2026 tax year · US · Updated June 11, 2026
Quarterly Estimated Tax Calculator
No employer withholds tax from self-employment income, so the IRS expects four payments a year. This calculator turns your expected profit into an exact per-quarter number, including the safe-harbor minimum that keeps you penalty-free.
Your numbers
Your 2026 quarterly payments
2026 due dates
- Q1 (January – March)April 15, 2026
- Q2 (April – May)June 15, 2026
- Q3 (June – August)September 15, 2026
- Q4 (September – December)January 15, 2027
Federal only; most states expect their own estimated payments (see our per-state pages). Estimates exclude credits, QBI, and itemized deductions, which usually lower the bill.
How the payment is calculated
Your quarterly payment has two ingredients: self-employment tax (15.3% Social Security and Medicare on 92.35% of net profit) and federal income tax on the same income after the deductible half of SE tax and your standard deduction come off. The calculator adds both, credits any W-2 withholding, and divides what remains across the four deadlines.
The safe harboris the part most people miss: you do not have to nail this year’s bill exactly. Pay in the smaller of 90% of this year’s tax or 100% of last year’s (110% if last year’s AGI topped $150,000) and no underpayment penalty applies, even if you owe more in April. When your income is rising, the prior-year target is usually cheaper and is locked in the day you file.
Ready to pay? IRS Direct Pay takes about three minutes. Our step-by-step quarterly tax guide walks through every payment method, and the SE tax calculator breaks down the Social Security and Medicare piece line by line.
These are estimates, not tax advice. The model excludes tax credits, the QBI deduction, and itemized deductions (each usually lowers the bill), and covers federal tax only; most states run their own estimated-tax schedules.
Where these numbers come from
Payments are computed with the Form 1040-ES logic: SE tax plus federal income tax, minus withholding, against the section 6654 safe-harbor targets. Every figure is transcribed from these sources:
- IRS Topic No. 306, Penalty for underpayment of estimated tax: the $1,000 threshold and the 90%/100% safe-harbor pair
- IRS Form 1040-ES (2026): the 110% prior-year rule above $150,000 AGI and the 2026 due dates
- IRS Topic No. 751, Social Security and Medicare rates: the 15.3% self-employment tax components
- IRS Rev. Proc. 2025-32: 2026 federal brackets and standard deductions
Constants last verified against these sources on June 11, 2026. Every value is also pinned by an automated test suite that fails if a rate in the calculator drifts from the figure we transcribed from the source.
Frequently asked questions
Who has to make quarterly estimated tax payments?
What is the safe harbor rule?
When are the 2026 payments due?
How do I actually send a payment?
What happens if I skip a quarter?
Does my W-2 withholding count toward the safe harbor?
Why is the safe-harbor payment lower than the full-coverage payment?
Does this calculator include state estimated taxes?
What if this is my first year self-employed?
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