Who has to pay quarterly estimated taxes?

Anyone with significant income that is not subject to withholding - the self-employed, freelancers, investors, and people with large RSU vests or capital gains - generally must pay estimated taxes each quarter to avoid an underpayment penalty.

What is the safe harbor rule?

You generally avoid a penalty if you pay at least 90% of the current year tax or 100% of last year tax (110% if your prior-year income was over $150,000), whichever is smaller, spread across the four quarterly deadlines.

When are the quarterly deadlines?

Federal estimated taxes are typically due in mid-April, mid-June, mid-September, and mid-January of the following year. Confirm the exact dates each year.

Quarterly Estimated Tax Calculator (2026)

Who needs to pay estimated taxes

The US tax system is pay-as-you-go. Employees have tax withheld from each paycheck, but income without withholding - self-employment, freelance work, investment gains, large RSU vests - can leave you owing a lot at filing, plus an underpayment penalty. To avoid that, the IRS expects quarterly estimated payments. This calculator estimates the total you owe and splits the remainder into four.

Worked example

A single filer expecting $100,000 of income with no withholding, taking the standard deduction:

Taxable income: $100,000 − $16,100 = $83,900
Total federal income tax: about $13,170
Already withheld: $0
Each quarterly payment: $13,170 ÷ 4 = about $3,293

If you also had a job withholding $8,000, only the remaining $5,170 would need to be covered by estimates - about $1,293 per quarter.

The safe harbor

You do not have to predict your tax perfectly. The safe harbor protects you from penalties if you pay the smaller of:

90% of this year tax, or
100% of last year tax (110% if your prior-year income exceeded $150,000).

Many people simply pay last year tax in four equal installments and settle up at filing - the simplest way to stay penalty-free.

How to handle a big one-off event

A large RSU vest or capital gain can blow past the 22% withheld and create a shortfall. Two approaches:

Make an extra estimated payment in the quarter the income lands.
Rely on the prior-year safe harbor and pay the balance at filing, accepting that you will owe.

What this leaves out

This estimates federal income tax on the income you enter. It does not include self-employment tax (use the 1099 tax calculator) or state estimated taxes, which have their own deadlines.

Common mistakes

Skipping estimates entirely and getting hit with an underpayment penalty.
Forgetting the 110% safe harbor rule for higher earners.
Underpaying after a big RSU vest because only 22% was withheld.

To understand the marginal rate behind your liability, see the effective tax rate calculator; for the supplemental withholding on a vest or bonus, see the bonus tax calculator.

Last reviewed January 2026. This calculator provides general educational estimates based on the inputs you enter and simplified assumptions. It is not financial, tax, legal or investment advice, and figures may differ from your actual liability. Verify with a licensed CPA or financial advisor before acting.

Estimated tax calculator