Quarterly Estimated Tax Calculator

Quarterly estimated taxes are prepayments of federal (and often state) income tax made four times per year by individuals who have income not subject to withholding. This includes self-employed workers, freelancers, independent contractors, small business owners, investors with significant dividends or capital gains, and retirees with pension or IRA distributions that are not being withheld. Because there is no employer withholding these taxes automatically, the IRS requires direct payments on a quarterly schedule.

The four federal estimated tax payment deadlines for the 2025 tax year are April 15, June 16, September 15, and January 15, 2026. Note that the due dates do not align perfectly with calendar quarters — Q1 covers January–March, Q2 covers April–May, Q3 covers June–August, and Q4 covers September–December. Missing these deadlines or underpaying can result in an IRS underpayment penalty, which is calculated based on the federal short-term interest rate plus 3 percentage points applied to the underpaid amount.

The IRS provides two safe harbor rules that protect against underpayment penalties. First, your total payments (withholding plus estimated payments) must equal at least 90% of your current year's tax liability. Second — and often easier to use for self-employed individuals with variable income — your payments can equal 100% of your prior year's total tax liability (110% if your prior year AGI exceeded $150,000). Meeting either safe harbor eliminates the underpayment penalty even if you owe a balance when you file.

1. Enter your expected total annual income from all sources including self-employment and investments.
2. Enter your expected deductions (business expenses, retirement contributions, etc.).
3. Select your filing status.
4. Enter your prior year total tax liability for safe harbor comparison.
5. Enter any W-2 withholding you will have this year from a part-time job or spouse's income.
6. Enter your self-employment income separately so the self-employment tax component can be correctly calculated.
7. Review your quarterly payment amount, safe harbor threshold, penalty risk, and the full payment schedule with due dates.

• Use the prior-year safe harbor: For freelancers with unpredictable income, basing quarterly payments on 100% (or 110%) of last year's tax is the safest approach — you eliminate the penalty risk regardless of how this year's income fluctuates.
• Set aside tax money in a high-yield savings account: A dedicated tax savings account earning 4–5% while you hold funds prevents you from accidentally spending tax money. Consider setting aside 25–30% of every invoice or payment received.
• Reduce Q4 liability with retirement contributions: SEP IRA contributions can be made up until the filing deadline (including extensions), providing a last-minute opportunity to reduce your annual tax liability and potentially lower your Q4 payment.
• Increase W-2 withholding as an alternative: If you have a W-2 job alongside self-employment, you can increase withholding at your day job to cover your self-employment tax liability — the IRS treats withholding as paid evenly throughout the year regardless of when it actually occurs.
• Annualized income installment method: If your income is heavily front- or back-loaded during the year, the annualized installment method allows you to pay quarterly estimates proportional to your actual income in each period, potentially reducing early-year payments. IRS Form 2210 AI is used for this calculation.