How to Calculate Estimated Quarterly Taxes (Form 1040-ES) Without Overpaying
Covers tax year 2026. General information, not personal tax advice.
The Core Idea in 30 Seconds
If no employer is withholding tax from your income, the IRS expects you to pay as you go, four times a year. You generally need to make estimated payments if you expect to owe at least $1,000 when you file, after subtracting withholding and refundable credits.
The easiest way to calculate it: take the total tax from last year’s return, divide by four, and pay that amount each quarter. That’s the “safe harbor,” and it protects you from underpayment penalties even if your income jumps. (If last year’s adjusted gross income was over $150,000, use 110% of last year’s tax instead.)
Who Has to Pay, and What “Safe Harbor” Means
Estimated taxes commonly apply to:
- Freelancers, gig workers, and independent contractors
- Small business owners and partners
- Landlords and investors with significant untaxed income
- Retirees without enough withholding on pensions or IRA withdrawals
You avoid the underpayment penalty if your withholding plus estimated payments add up to at least the smaller of:
| Safe harbor test | Amount |
|---|---|
| Current-year test | 90% of your 2026 tax |
| Prior-year test | 100% of your 2025 tax |
| Prior-year test, higher incomes | 110% of your 2025 tax if your 2025 AGI was over $150,000 ($75,000 if married filing separately) |
The prior-year test only works if your 2025 return covered a full 12 months. Farmers and fishers have a separate rule (66⅔% in place of 90%).
2026 due dates:
| Income earned | Payment due |
|---|---|
| January 1 – March 31 | April 15, 2026 |
| April 1 – May 31 | June 15, 2026 |
| June 1 – August 31 | September 15, 2026 |
| September 1 – December 31 | January 15, 2027 |
Notice the “quarters” aren’t equal. The second one is only two months long, which catches people every June. When a date lands on a weekend or holiday, it moves to the next business day.
Step-by-Step: Two Ways to Calculate
Method A: The safe harbor shortcut (simplest)
- Find total tax on your 2025 Form 1040.
- Check your 2025 AGI. Over $150,000? Multiply the total tax by 1.10.
- Subtract any tax that will be withheld from paychecks or pensions in 2026.
- Divide by 4. That’s your quarterly payment.
Example: Your 2025 total tax was $12,000 and your AGI was $95,000. You have no withholding. Pay $3,000 each quarter. If your AGI had been $180,000, you’d pay $13,200 for the year, or $3,300 per quarter.
You may still owe a balance in April if you earned more this year, but there’s no underpayment penalty.
Method B: Estimate this year’s actual tax (more accurate)
Use this when your income dropped, or you’re in your first year of self-employment.
- Estimate net self-employment income for the full year (revenue minus business expenses).
- Figure self-employment tax: net earnings × 92.35% × 15.3%. On $60,000 of net profit, that’s about $8,478. This covers Social Security and Medicare.
- Estimate income tax: take total income, subtract half of your self-employment tax and your standard or itemized deduction, then apply the tax brackets. The worksheet in Form 1040-ES walks through this line by line.
- Add the two taxes together, subtract credits and any withholding.
- Multiply by 90% and divide by four.
How to send the payment
- IRS Direct Pay (free, from a bank account) at irs.gov/payments
- Your IRS Online Account
- Debit or credit card (processor fee applies)
- Mail a check with a Form 1040-ES voucher. Mail it early: the postmark date is when USPS processes it, not when you drop it off.
Choose estimated tax as the payment type and the correct tax year when you pay. Double-check the year before you submit, because a payment applied to the wrong year is a hassle to fix.
Pro Tips & FAQs
Tip: Set aside a fixed percentage of every payment you receive in a separate savings account. Many freelancers use 25–30% as a starting point, then adjust once they’ve done the math.
Tip: Have a W-2 job too? Raising your withholding with a new Form W-4 can replace estimated payments entirely. Withholding counts as paid evenly through the year no matter when it’s taken out.
Tip: Most states with an income tax have their own estimated payments on a similar schedule.
What happens if I miss a quarterly payment?
The IRS charges an underpayment penalty, which works like interest on the amount you were short for the time it was late. Pay as soon as you can to stop it from growing.
Do I have to pay the same amount each quarter?
No. If your income is uneven, the annualized installment method on Form 2210 lets you pay less in slow quarters and more in busy ones.
Do I need to mail Form 1040-ES to the IRS?
No. The form is a worksheet for your records. If you pay electronically, you don’t send anything. Vouchers are only for mailed checks.
Can I just pay it all in April?
You can, but if you owe $1,000 or more and didn’t meet a safe harbor, you’ll be charged an underpayment penalty.
I started freelancing mid-year. When do I start?
Begin with the payment period in which you first had income. To avoid a penalty for the earlier periods, use the annualized income installment method and file Form 2210 with Schedule AI with your return.
Sources: IRS Estimated Tax FAQs, IRS Topic No. 306, and the current Form 1040-ES.