Quarterly Estimated Tax Calculator

Estimate your 2026 quarterly estimated tax payments: self-employment tax plus federal income tax, less withholding, with the IRS safe harbor check. Example: $80,000 of net profit owes about $4,700 a quarter.

How to use the Quarterly Estimated Tax Calculator

1. Enter the net profit you expect from self-employment this year.
2. Add W-2 wages and any tax already withheld.
3. Enter last year’s total tax if you want the prior-year safe harbor.
4. Press Calculate to see how much to pay each quarter.

Formula and method

Estimated tax = self-employment tax + federal income tax – withholding. To avoid the underpayment penalty you generally pay the smaller of 90% of this year’s tax or 100% of last year’s tax (110% if last year’s AGI was over $150,000), split into four payments.

Worked example: $80,000 net profit, single

Estimated tax due dates

When a date falls on a weekend or holiday, the deadline moves to the next business day.

Who must pay estimated tax

You generally need to pay quarterly if you expect to owe $1,000 or more after subtracting withholding and credits, and your withholding will cover less than the lesser of 90% of this year’s tax or 100% of last year’s. This applies to freelancers, contractors, landlords and investors with income not subject to withholding.

Frequently asked questions

How do I calculate quarterly estimated taxes?

Estimate your total tax (SE tax plus income tax), subtract withholding, and divide the amount you must pay by four.

When are quarterly taxes due in 2026?

April 15, June 15 and September 15, 2026, and January 15, 2027.

What is the safe harbor rule?

You avoid the penalty if you pay at least 90% of this year’s tax or 100% of last year’s tax (110% if last year’s AGI was over $150,000).

What if I underpay?

The IRS charges an underpayment penalty based on the amount and how late each payment is.

Can I pay more in one quarter?

Yes. Payments can be uneven, but the penalty is calculated per quarter, so even payments are simplest.

How do I pay?

Through IRS Direct Pay, your IRS online account, or by mail with a voucher.

Does this include state estimated tax?

No. Many states require their own quarterly payments.

Sources

• IRS: Estimated taxes
• IRS: Underpayment of estimated tax by individuals

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