IRS Quarterly Estimated Tax Calculator

Pay min(annual liability, 100% of prior year tax, 110% if prior AGI > $150k) ÷ 4 per quarter to avoid underpayment penalty.

Safe harbor (lesser of)
Need to pay (annual)
Per quarter

2025 quarterly due dates — Apr 15, Jun 16, Sep 15, Jan 15 2026. Underpayment penalty avoided if total paid ≥ safe harbor amount.

About this tool

IRS Quarterly Estimated Tax Calculator is a single-purpose utility on instant.tw, a free toolbox of calculators, converters, generators, and quick lookups. Everything works in your browser — nothing is uploaded, nothing is stored on a server unless explicitly noted.

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