Quarterly Tax Calculator
Work out what to send the IRS each quarter — and the number that keeps penalties off your return.
Pay this each quarter
$3,486
Four payments of $3,486, totalling $13,945 for the year.
Your 2026 payment schedule
Jan 1 - Mar 31
Apr 1 - May 31
Jun 1 - Aug 31
Sep 1 - Dec 31
How we got there
- Net self-employment income
- $75,000
- Self-employment tax
- $10,597
- Federal income tax
- $4,898
- State tax
- $0
- Total 2026 tax
- $15,495
- Less W-2 withholding
- $0
- Already paid this year
- $0
- Still to pay
- $13,945
Estimate only, for the 2026 tax year. Assumes income arrives evenly across the year — if yours is lumpy, the annualized income installment method (Form 2210, Schedule AI) may lower an individual quarter. Due dates shift to the next business day when they fall on a weekend or federal holiday. Confirm with a tax professional.
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What is the Quarterly Tax Calculator?
The Quarterly Tax Calculator turns a year of expected self-employment income into four estimated tax payments, each with its IRS due date. It also calculates your safe harbor — the minimum you can pay and still be protected from an underpayment penalty, even if you end up earning more than you planned.
How is it calculated?
Enter the income you expect across all of 2026 and the expenses you will write off. The calculator works out self-employment tax, federal income tax, and state tax, subtracts any W-2 withholding, and divides what remains across four payments. Add last year's total tax and it also applies the safe-harbor rule, showing whichever of the two IRS tests gives you the lower required payment.
Worked example: $90,000 of freelance income with $15,000 of expenses
- Start with net profit
$90,000 billed minus $15,000 of deductible expenses leaves $75,000 of net self-employment profit. That is the figure both taxes are built on.
- Self-employment tax
$75,000 carries $10,597 in Social Security and Medicare. This is the part that surprises people — it applies before any income tax.
- Federal income tax
After the half-SE-tax adjustment, the qualified business income deduction, and the $16,100 standard deduction, income tax comes to $4,898. Total 2026 tax: $15,495.
- Apply the safe harbor
Last year's tax was $16,000 on $95,000 of AGI. The IRS lets you pay the lower of 90% of this year ($13,945) or 100% of last year ($16,000). The lower figure is $13,945.
- Divide into four
$13,945 across four quarters is $3,486 per payment, due April 15, June 15, September 15, and January 15 of the following year.
- What this protects you from
Pay that and the IRS cannot charge an underpayment penalty, even if the year finishes far better than forecast. Any remaining balance is simply settled when you file.
Your 2026 payment schedule
| Quarter | Income period | Due date | Payment |
|---|---|---|---|
| Q1 | January 1 – March 31 | April 15, 2026 | $3,486 |
| Q2 | April 1 – May 31 | June 15, 2026 | $3,486 |
| Q3 | June 1 – August 31 | September 15, 2026 | $3,486 |
| Q4 | September 1 – December 31 | January 15, 2027 | $3,486 |
Frequently Asked Questions
Who has to pay quarterly estimated taxes?
Anyone who expects to owe at least $1,000 in tax after subtracting withholding and refundable credits. In practice that means most freelancers, contractors, and small business owners without a W-2 job covering the shortfall. Having a W-2 job with enough withholding can remove the requirement entirely.
What is the safe harbor rule?
Pay either 90% of what you owe this year, or 100% of last year's total tax — 110% if your prior-year AGI was over $150,000 — and the IRS will not charge an underpayment penalty regardless of how the year turns out. The prior-year test is the useful one, because you already know the number.
What happens if I miss a quarterly payment?
The IRS charges interest on the shortfall from that quarter's due date until it is paid, currently assessed on Form 2210. It is not a flat fine, so a payment made a few weeks late costs relatively little. Skipping the year entirely is what gets expensive.
My income is uneven — do I still pay four equal amounts?
You do not have to. The annualized income installment method on Form 2210, Schedule AI, lets you match each payment to what you actually earned in that period. It is more paperwork, but it prevents overpaying early in a year that is back-loaded.
Do quarterly payments cover state tax too?
No. Federal estimated payments go to the IRS; most states with an income tax run their own separate estimated payment system with their own vouchers and, occasionally, different due dates. The state figure shown here is an estimate to help you budget.