Quarterly Estimated Tax Calculator
Calculate IRS quarterly estimated tax payments for self-employed, freelance, and 1099 income. Apply the 110% (or 100%) safe harbor based on prior-year AGI to avoid underpayment penalties — free, private, and instant for tax year 2026.
2026 IRS Quarterly Estimated Tax Due Dates
Self-employed individuals, freelancers, gig workers, partnership members, and S-corp shareholders must pay federal income tax in four quarterly installments using IRS Form 1040-ES. Per the IRS Estimated Taxes guidance, the 2026 due dates are: Q1: April 15, 2026 (income earned January-March), Q2: June 15, 2026 (April-May income), Q3: September 15, 2026 (June-August income), Q4: January 15, 2027 (September-December income). When the 15th falls on a weekend or federal holiday, the deadline shifts to the next business day. You can pay online at IRS Direct Pay, by mail with Form 1040-ES voucher, or via EFTPS for businesses.
Safe Harbor Rules — How to Avoid Underpayment Penalties
The IRS waives the underpayment penalty if you meet either of two safe harbor tests. Test 1: Pay at least 90% of current year tax through withholding plus estimated payments. Test 2: Pay 100% of prior year tax (or 110% if your prior year AGI exceeded $150,000, or $75,000 for married filing separately). The 110% high-income safe harbor catches most established freelancers and consultants — verify your prior-year AGI to know which threshold applies. The penalty for underpayment is calculated separately for each quarter using the federal short-term rate plus 3% per the IRS Form 2210 instructions. As of Q1 2026, this rate is approximately 8% annualized, applied to the underpayment amount and number of days late.
Self-Employment Tax — The Hidden 15.3% Cost
In addition to federal income tax, self-employed earners pay self-employment tax of 15.3% on net earnings up to the Social Security wage base ($176,100 in 2026 per the SSA wage base) and 2.9% Medicare tax on all earnings above. High earners pay an additional 0.9% Medicare surtax on combined self-employment plus W-2 income above $200,000 single / $250,000 married. This calculator includes the SE tax deduction (you deduct one-half of SE tax for income tax purposes) and projects the full quarterly liability. Tip: contributing to a SEP-IRA or solo 401(k) can shelter $69,000-$76,500 of self-employment income in 2026, dramatically reducing both income tax and the underpayment risk. Last updated 2026-07-03.
Strategies to Minimize Estimated Tax Stress
Three strategies reduce the burden of quarterly estimates. Increase W-2 withholding (if you also have a job): withholding is treated as paid evenly throughout the year, so a year-end Form W-4 adjustment can replace quarterly estimates. Use the Annualized Income Installment Method (Schedule AI of Form 2210) if your income is lumpy — e.g., a freelancer who books 60% of revenue in Q4 can pay smaller Q1-Q3 estimates without penalty. Direct withholding from IRA distributions: when taking IRA withdrawals, ask the custodian to withhold federal tax — like W-2 withholding, this counts as paid evenly. Contractors who follow these strategies often eliminate Q1-Q2 estimated payments entirely.
Mid-Year Checkpoint (July): Are You On Track for Q3?
By early July, half the tax year is complete and Q2's June 15 payment is behind you — the ideal time to check whether Q3 (due September 15) needs an adjustment. Add up: (a) year-to-date net self-employment income (Jan-Jun), (b) all estimated payments made so far. If year-to-date income has run 20% above your original annual projection, bump Q3 and Q4 to cover the gap; if it has run below, trim Q3 to conserve cash. The calculator above lets you re-project the full year in seconds — plug in actual YTD numbers and see whether the remaining two quarters clear the safe harbor. Per IRS Publication 505 (Tax Withholding and Estimated Tax), the annualized method allows you to true up mid-year without penalty — but only if you file Schedule AI with your return. Better to catch a shortfall in July than discover it in April.
Estimated Tax Calculator: State-Level Quarterly Payments You Might Owe
Federal quarterly estimates get the headlines, but roughly 40 states also require quarterly estimated payments if you owe more than a threshold — often $500 or $1,000. California, New York, New Jersey, Massachusetts, and Illinois all charge state-level underpayment penalties on top of federal ones. State due dates usually match federal (April 15, June 15, Sept 15, Jan 15) but Iowa, Arkansas, and a few others have their own schedules. If your net freelance income tops $50,000 and you live in a state with income tax, budget an extra 4-9% for state estimates alongside the federal number this calculator produces. Check your state DOR site or use our state-specific paycheck calculators for exact rates.