Quarterly Estimated Tax Calculator
Calculate your Q1–Q4 estimated tax payments for 2026 — self-employment tax plus federal income tax for freelancers and 1099 contractors.
Quarterly Tax Deadlines for 2026
The IRS requires self-employed workers to prepay taxes in four installments. Missing any deadline triggers an underpayment penalty at the current federal funds rate plus 3% (approximately 8% annualized in 2026). The penalty is calculated per-quarter on the amount underpaid, so even catching up in Q4 doesn't eliminate earlier quarter penalties.
Safe Harbor Rule
To guarantee no penalty, pay 100% of last year's tax liability (110% if AGI exceeded $150,000) spread evenly across four quarters. This is called the safe harbor and protects you even if your income rises significantly during the year. Many self-employed workers use safe harbor for predictability and then reconcile at filing.
How to Pay
Pay estimated taxes via IRS Direct Pay (free), EFTPS (Electronic Federal Tax Payment System, free), or by mailing Form 1040-ES with a check. EFTPS allows scheduling future payments — set up all four at the start of the year to avoid missing deadlines.