Quarterly Estimated Tax Calculator 2026

Who Needs to Pay Quarterly Taxes?

The IRS requires you to “pay as you go” throughout the year. If you're an employee, your employer handles this through paycheck withholding. But if you're self-employed, a freelancer, or have other income without withholding, you need to make quarterly estimated tax payments yourself.

You likely need to pay quarterly if:

• You expect to owe $1,000 or more in taxes after subtracting withholding
• You're self-employed or run a business
• You have significant freelance, gig economy, or 1099 income
• You have rental income, investment gains, or other non-wage income

Self-Employment Tax Explained

Self-employment tax is the Social Security and Medicare tax for self-employed individuals. When you work for an employer, they pay half of these taxes (7.65%), and you pay the other half through payroll withholding. When you're self-employed, you pay both halves—a total of 15.3%.

The good news: You can deduct half of your self-employment tax (the “employer portion”) when calculating your adjusted gross income. This calculator automatically accounts for this deduction.

The Safe Harbor Rules

The IRS won't charge you an underpayment penalty if you meet one of these “safe harbor” thresholds:

• 90% of current year tax: Pay at least 90% of your total tax for the current year
• 100% of prior year tax: Pay at least 100% of your total tax from last year (or 110% if your prior year AGI exceeded $150,000)
• Owe less than $1,000: If you owe less than $1,000 when you file, no penalty applies

This calculator shows you the cheapest option to meet safe harbor—so you don't overpay unnecessarily.

What Happens If You Don't Pay?

Missing quarterly payments doesn't mean you'll go to jail or face severe consequences. However, you will likely owe an underpayment penalty when you file your return. The penalty is essentially interest on the amount you should have paid, calculated at the federal short-term rate plus 3 percentage points.

The best approach: Pay your estimated taxes on time, or catch up as soon as possible if you fall behind. Even a late payment is better than no payment.