Estimated tax calculator (Form 1040-ES): what to pay and when
Two safe harbors, and only the smaller one binds. Fill in the six numbered lines and the four vouchers work themselves out — including what is already short at a date that has passed.
Figures verified · next scheduled change (the IRS confirms the following year’s dates in Form 1040-ES)
The 2026 dates
Four installments, each covering a different and unequal slice of the year — the second period is two months long, the third three, the fourth four. The dates are the 15th of April, June and September and the following January 15, moved to the next business day when one lands on a weekend or a District of Columbia legal holiday.
| Installment | Income earned | Due | Moved? |
|---|---|---|---|
| Q1 | Jan 1, 2026 – Mar 31, 2026 | Wednesday, April 15, 2026 | no |
| Q2 | Apr 1, 2026 – May 31, 2026 | Monday, June 15, 2026 | no |
| Q3 | Jun 1, 2026 – Aug 31, 2026 | Tuesday, September 15, 2026 | no |
| Q4 | Sep 1, 2026 – Dec 31, 2026 | Friday, January 15, 2027 | no |
| January waiver | file and pay in full instead | Monday, February 1, 2027 | January 31, 2027 is a Sunday |
The 2026 and 2027 dates, with every weekend and holiday shift worked out →
The figures behind this tool
| Figure | Value | Applies | Source |
|---|---|---|---|
| Paying 90 % of the current year’s total tax avoids the underpayment penalty. | 90% of this year's total tax | long-standing → open | IRC §6654(d)(1)(B)(i); IRS Pub 505; Form 2210 verified 2026-09-06 |
| Paying 100 % of the prior year’s total tax avoids the underpayment penalty. | 100% of last year's total tax | long-standing → open | IRC §6654(d)(1)(B)(ii) verified 2026-09-06 |
| The prior-year safe harbor rises to 110 % when prior-year AGI was over the high-income threshold. | 110% of last year's total tax | long-standing → open | IRC §6654(d)(1)(C) verified 2026-09-06 |
| Prior-year AGI above this triggers the 110 % prior-year safe harbor. | $150,000 ($75,000 if married filing separately) | long-standing → open | IRC §6654(d)(1)(C)(i)–(ii) verified 2026-09-06 |
| Prior-year AGI above this amount makes the prior-year safe harbor 110% for a married-filing-separately return (half of the $150,000 threshold). | $75,000 | long-standing → open | IRC §6654(d)(1)(C)(ii) (uscode.house.gov) verified 2026-09-06 |
| No underpayment penalty when the balance after withholding and credits is under this amount. | $1,000 | long-standing → open | IRC §6654(e)(1) verified 2026-09-06 |
| First estimated-tax installment for tax year 2026 — a Wednesday. | April 15, 2026 | 2026-01-01 → 2026-04-15 | 2026 Form 1040-ES; IRS "When to pay estimated tax" verified 2026-09-06 |
| Second estimated-tax installment for tax year 2026 — a Monday. | June 15, 2026 | 2026-01-01 → 2026-06-15 | 2026 Form 1040-ES verified 2026-09-06 |
| Third estimated-tax installment for tax year 2026 — a Tuesday. | September 15, 2026 | 2026-01-01 → 2026-09-15 | 2026 Form 1040-ES verified 2026-09-06 |
| Fourth estimated-tax installment for tax year 2026 — a Friday. | January 15, 2027 | 2026-01-01 → 2027-01-15 | 2026 Form 1040-ES verified 2026-09-06 |
| Filing the return and paying the balance in full by the waiver date removes the January installment requirement. | File and pay in full by February 1, 2027 | 2026-01-01 → 2027-02-01 | 2026 Form 1040-ES verified 2026-09-06 |
| A first-year filer with no full prior tax year cannot use the prior-year safe harbor. | The prior-year safe harbor needs a full 12-month prior tax year and a filed return | long-standing → open | IRC §6654(d)(1)(B) flush text verified 2026-09-06 |
| Tax withheld during the year is spread evenly across the four installment dates unless you elect otherwise. | Withholding counts as paid in equal parts on each installment date | long-standing → open | IRC §6654(g)(1); Form 2210 instructions verified 2026-09-06 |
| The annualized income installment method for uneven income. | Form 2210, Schedule AI | long-standing → open | IRS Form 2210 verified 2026-09-06 |
| The IRC §6621 underpayment interest rate is reset every quarter by IRS news release. | Resets quarterly — check the current IRS rate | long-standing → open | IRC §6621(a)(2); IRS — quarterly interest rates verified 2026-09-07 |
What this does not do
- It does not compute your tax. Line 05 is your own estimate of total tax for the year; the sub-panel that helps you get there is arithmetic on your own effective rate, not a return.
- It does not compute a dollar penalty. That needs the IRC §6621 underpayment rate, which the IRS resets every quarter.
- It is federal only. State estimated payments have their own schedules, thresholds and forms.
- It does not know about farming and fishing income, casualty waivers, or the special rules for estates and trusts, all of which change the dates or the percentages.
- It does not file or pay anything. Nothing you type here reaches the IRS or leaves your browser.
03In this section
Questions
What is the estimated-tax safe harbor?
Two targets, and you only have to hit the smaller one. Withholding plus timely installments that cover 90% of this year’s total tax avoid the underpayment penalty; so does covering 100% of last year’s total tax, which becomes 110% of last year’s total tax when your prior-year adjusted gross income was over $150,000 ($75,000 if married filing separately). Hit either and the penalty cannot apply, however the year turns out.
Is there an amount I can owe without any penalty?
Yes. Under IRC §6654(e)(1) there is no addition to tax at all when your balance due after withholding and credits is under $1,000. That figure is statutory and has never been indexed, so it does not move with inflation.
I have no prior-year return — can I use the 100% harbor?
No. IRC §6654(d)(1)(B) gives the prior-year harbor only for a full 12-month prior tax year for which a return was filed. A first-year freelancer has one target only: 90% of this year’s tax. That is why line 04 on this page defaults to “No” — it is the answer that cannot understate what you owe.
Does withholding count toward the quarterly deadlines?
Withholding is treated as paid in equal parts on each of the four installment dates, whenever it was actually withheld (IRC §6654(g)(1)). That makes raising your W-2 or pension withholding late in the year the one move that reaches backwards and cures an earlier shortfall — an estimated payment cannot do that.
Why does this tool not show a dollar penalty?
Because the penalty is interest, computed at the IRC §6621 underpayment rate, and that rate is re-set by IRS news release every quarter. Publishing a dollar figure would mean publishing a rate we cannot promise is current, so the tool gives the reliable part instead: the target, the per-quarter payment, and what is short at each date.
Sources
- IRS Form 1040-ES — Estimated Tax for Individuals · accessed 2026-09-07
- IRS Publication 505 — Tax Withholding and Estimated Tax · accessed 2026-09-07
- IRS Form 2210 and Schedule AI — Underpayment of Estimated Tax · accessed 2026-09-07
- IRC §6654 — Failure by individual to pay estimated income tax · accessed 2026-09-07
Also this year
Money calendarevery deadline this year, with day counts→The 2026 numbersevery threshold we track, on one page→Information, not advice. Confirm with IRS Form 1040-ES and Publication 505, or a tax professional.