Quarterly Estimated Tax Calculator (2026)

Split your 2026 tax bill into 1040-ES quarterly payments — with IRS safe harbor rules and W-2 withholding offsets built in.

$
$
$
%
Pay each quarter
$5,591.14
¼ of your estimated tax after withholding
Total estimated tax
$22,364.55
SE tax + federal + state
After withholding
$22,364.55
the amount you must cover

1040-ES due dates

  • Payment 1 — April 15, 2026$5,591.14
  • Payment 2 — June 15, 2026$5,591.14
  • Payment 3 — September 15, 2026$5,591.14
  • Payment 4 — January 15, 2027$5,591.14

How this quarterly tax calculator works

Enter your expected net 1099 income for the year. The calculator estimates your full 2026 federal tax using the same engine as the 1099 tax calculator — self-employment tax, income tax brackets, QBI and the standard deduction — adds an optional state rate, subtracts any W-2 withholding you expect, and divides the remainder into four equal quarterly payments.

The safe harbor option

If your income is growing, paying one quarter of this year's estimate may be far more than you legally need to pay right now. The safe harbor rule lets you avoid penalties by paying 100% of last year's total tax (110% if your AGI exceeded $150,000). Enable it, enter last year's tax, and the calculator recommends the smaller of the two amounts per quarter — you settle the difference when you file.

Payment dates to remember

Your four payments are due April 15, June 15, September 15, 2026 and January 15, 2027. Payments are made online via IRS Direct Pay, by card (with a fee), or by mailing a 1040-ES voucher. Mark the reminder dates now — underpayment interest accrues per quarter from each due date.

Frequently asked questions

Who has to pay quarterly estimated taxes?

Anyone who expects to owe $1,000 or more in tax after withholding and credits must make quarterly estimated payments. That includes most freelancers and 1099 contractors, who have no employer withholding at all, as well as employees with significant side income.

What are the 1040-ES due dates for 2026?

April 15, June 15 and September 15, 2026, plus January 15, 2027 for the fourth quarter. If a due date falls on a weekend or holiday, the payment is due the next business day.

What is the IRS safe harbor rule?

You avoid underpayment penalties by paying at least 90% of this year’s tax, or 100% of last year’s total tax (110% if your adjusted gross income was over $150,000), whichever is smaller. The safe harbor is a popular strategy when your income is growing — you pay based on last year’s lower number and settle the difference at filing time.

How do I calculate my quarterly tax payment?

Estimate your annual tax (self-employment tax plus income tax plus state tax), subtract any W-2 withholding, and divide by four. This calculator runs the 2026 federal math for you and, if you enable it, applies the safe harbor rule to find the smallest payment that avoids penalties.

What happens if I miss a quarterly estimated payment?

The IRS charges underpayment interest on the amount you should have paid, calculated per quarter from each due date. The penalty is not fixed — it follows interest rates — but it is avoidable by paying on time or meeting the safe harbor. If you have already missed one, paying the rest now limits the damage.

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Estimates for planning only — not tax, legal, or financial advice. Figures reflect tax year 2026 (IRS Rev. Proc. 2025-32) and apply to U.S. federal taxes; your situation may differ. Consult a qualified tax professional before making decisions.