Quarterly estimated tax calculator (Form 1040-ES)

Quarterly estimated tax calculator (Form 1040-ES): what it is for

Enter the total federal tax you expect for this year (income tax plus self-employment tax), the total tax from last year's return, whether last year's AGI was over $150,000, and the federal tax already withheld from paychecks. The calculator applies the safe harbor rules, picks the smaller required amount and divides it into four payments with their due dates.

It also shows the amount needed to cover 100% of this year's tax, so you can pay more and avoid a balance due in April. Use the self-employment tax and federal income tax calculators to estimate this year's tax.

How to use

1. Enter this year's and last year's tax.
2. Enter withholding and the AGI test.
3. Read each quarterly payment and due date.

When to use it

• Freelancers and 1099 contractors.
• Small business owners.
• Rental and investment income.

Frequently asked questions

Who has to pay estimated taxes?

Generally anyone who expects to owe at least $1,000 in federal tax for the year after withholding and credits: freelancers, gig workers, independent contractors, small business owners, landlords and investors with income that has no withholding.

What are the safe harbor rules?

You avoid the underpayment penalty if your withholding plus estimated payments cover at least 90% of this year's tax or 100% of last year's tax, whichever is smaller. If last year's AGI was over $150,000 ($75,000 if married filing separately), the prior-year rule is 110%.

When are the 2026 estimated tax payments due?

April 15, 2026, June 15, 2026, September 15, 2026 and January 15, 2027 for calendar-year taxpayers. When a due date falls on a weekend or legal holiday, it moves to the next business day.

Is it really free?

Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 tools are free and run right in your browser.

Similar tools