Who has to pay estimated tax
The U.S. tax system is pay-as-you-go. Employers withhold tax from every paycheck, but nobody withholds from 1099 income, gig work, rental profits or investment income. If you expect to owe $1,000 or more for 2026 after subtracting withholding and refundable credits, the IRS expects you to send estimated tax payments during the year with Form 1040-ES, or online through IRS Direct Pay or your IRS online account.
2026 due dates
| Payment | Covers income earned | Due date |
|---|---|---|
| 1st | January 1 – March 31 | April 15, 2026 |
| 2nd | April 1 – May 31 | June 15, 2026 |
| 3rd | June 1 – August 31 | September 15, 2026 |
| 4th | September 1 – December 31 | January 15, 2027 |
The "quarters" are not equal: the second covers two months and the fourth covers four. You do not have to make the January 15, 2027 payment if you file your 2026 return by February 1, 2027 and pay the full balance with it.
How much to pay: the safe-harbor rules
You avoid an underpayment penalty if your withholding plus timely estimated payments add up to at least the smaller of:
- 90% of the tax on your 2026 return, or
- 100% of the tax on your 2025 return, if that return covered all 12 months. This rises to 110% if your 2025 adjusted gross income was more than $150,000 ($75,000 married filing separately).
Required annual payment = min(90% × 2026 tax, 100% or 110% × 2025 tax); each quarter = (required payment − withholding) ÷ 4
The prior-year rule is the one to use when income is growing or hard to predict: pay a quarter of last year's tax each time and you cannot be penalized, even if you owe more in April. The calculator works out this year's tax with the same method as the 1099 tax calculator, then picks the smaller target.
Worked example
A single freelancer expects $60,000 of 2026 profit and has no job. Her 2025 return showed total tax of $9,000, and her 2025 income was under $150,000.
- Estimated 2026 tax: $8,477.73 self-employment tax + $3,559.47 income tax = $12,037.20
- 90% of that: $10,833.48
- 100% of 2025 tax: $9,000, the smaller figure
- Quarterly payment: 9,000 ÷ 4 = $2,250 on each due date
- Balance in April 2027: 12,037.20 − 9,000 = about $3,037, with no penalty
If she had no 2025 tax to compare (for example, her first year after school), the target would be 90% of this year's tax, $10,833.48, or $2,708.37 a quarter.
If you also have a job
Withholding counts as paid evenly through the year no matter when it was taken out. That makes a W-2 job a useful tool: instead of making estimated payments, you can give your employer a new Form W-4 with extra withholding in Step 4(c) to cover the side income. Enter the full year's expected withholding above and the calculator shows how much is still needed from estimated payments.
Uneven income
If most of your income arrives late in the year, equal payments may overpay early quarters. The annualized income installment method (Form 2210, Schedule AI) lets you base each payment on income actually earned up to that point. It takes more work but can remove a penalty for early quarters. Seasonal businesses, people who start freelancing mid-year and anyone with a large December contract are the usual users.
The penalty
The underpayment penalty works like interest: the federal short-term rate plus 3 percentage points, charged on each late or short payment from its due date until it is paid or until April 15, 2027. It is figured on Form 2210. Paying late is cheaper than not paying, so if you missed a quarter, pay as soon as you can rather than waiting.
Common mistakes
- Waiting until April. The penalty applies to each quarter, so paying everything with the return still means a penalty for the quarters you skipped.
- Using last year's tax after a big jump in income with AGI above $150,000. The safe harbor then needs 110% of last year's tax, not 100%.
- Forgetting state estimates. Most states with an income tax have their own quarterly payments and due dates.
- Paying from the wrong year. When paying online, pick "estimated tax" and the 2026 tax year so the payment is not applied to an old balance.
This calculator covers federal estimated tax for individuals. Farmers and fishermen use 66⅔% instead of 90% and have a single January due date. Corporations use Form 1120-W.
Frequently asked questions
When are 2026 quarterly estimated taxes due?
April 15, 2026, June 15, 2026, September 15, 2026 and January 15, 2027. The January payment is optional if you file your 2026 return by February 1, 2027 and pay everything due.
How do I calculate my quarterly estimated tax?
Estimate your full-year tax, including self-employment tax. Take the smaller of 90% of it and 100% of last year's total tax (110% if last year's AGI was over $150,000), subtract expected withholding and divide by four.
What happens if I don't pay quarterly taxes?
The IRS charges an underpayment penalty, which is interest at the federal short-term rate plus 3 points on each late quarter. You still owe the tax itself when you file.
Do I need to pay estimated tax in my first year of freelancing?
If you had no tax liability for the full prior year (and were a U.S. citizen or resident all year), you owe no penalty for 2026 even without estimates. Paying anyway avoids a large bill in April.
Can I pay all my estimated tax at once?
Yes. You can pay the whole year's estimate by April 15, 2026, or make extra payments at any time. Only paying too little, too late, is penalized.
Sources
- Internal Revenue Service. Form 1040-ES (2026), Estimated Tax for Individuals: who must pay, safe-harbor rules and due dates.
- Internal Revenue Service. Publication 505, Tax Withholding and Estimated Tax.
- Internal Revenue Service. Form 2210, Underpayment of Estimated Tax by Individuals; Underpayment of estimated tax penalty.
- Internal Revenue Service. Revenue Procedure 2025-32: 2026 brackets and standard deductions.
Last reviewed 29 October 2026. Results are estimates; see our disclaimer.