Quarterly Estimated Tax Calculator for 2026
Find the smallest quarterly payment that keeps you clear of underpayment penalties in 2026, based on this year's projected tax or last year's actual tax.
Safe harbor target $14,000, based on 100% of last year's tax.
| 2026 payment | Due | Amount |
|---|---|---|
| Q1 | April 15, 2026 | $3,500 |
| Q2 | June 15, 2026 | $3,500 |
| Q3 | September 15, 2026 | $3,500 |
| Q4 | January 15, 2027 | $3,500 |
| Projected 2026 federal tax | |
|---|---|
| Self-employment tax | $12,717 |
| Income tax (after QBI of $13,508) | $6,599 |
| Total projected | $19,316 |
Uses the §6654 safe harbor: the smaller of 90% of 2026 tax or 100% of 2025 tax (110% if 2025 AGI was over $150,000, or $75,000 married filing separately). Withholding is treated as paid evenly. Federal only; standard deduction assumed. Educational estimate, not tax advice.
What the calculator does.
- Projects 2026 federal tax: self-employment tax, Additional Medicare tax and income tax after the standard deduction and QBI.
- Compares 90% of that projection with 100% of your 2025 tax (110% if 2025 AGI was over $150,000) and uses the smaller number.
- Subtracts withholding and splits the rest across the four 2026 due dates.
Common questions
When are 2026 estimated taxes due?
April 15, June 15 and September 15, 2026, and January 15, 2027.
Do I need to pay state estimated tax too?
Usually, yes. Most states with an income tax have their own quarterly system with similar dates. This calculator covers federal tax only.
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