Estimated tax payment calculator
Find the smallest quarterly payments that protect you from underpayment penalties for 2026, at both the IRS and the Colorado Department of Revenue.
Your 2026 payments
Assumes equal payments and withholding spread evenly through the year. Income that arrives unevenly can use the annualized method instead. Figures: 2026 Form 1040-ES and Colorado DR 0104EP. Not tax advice.
Not sure what you will owe for 2026?
A planning projection gives you a real number for this year, and the estimated payments to match.
The safe harbor rules for 2026
- IRS: the smaller of 90% of 2026 tax or 100% of 2025 tax (110% if 2025 AGI was over $150,000).
- Colorado: the smaller of 70% of 2026 tax or 100% of 2025 tax (110% if 2025 federal AGI was over $150,000).
- Payments are due April 15, June 15, September 15, 2026 and January 15, 2027.
Common questions
Who has to make estimated tax payments?
Generally anyone who expects to owe at least $1,000 in federal tax for 2026 after withholding and credits, which usually means business owners, self-employed people and anyone with significant investment income. Colorado applies a similar test to Colorado tax above $1,000.
What is a safe harbor?
Paying at least the safe harbor amount on time avoids the underpayment penalty even if you owe more when you file. Federally it is the smaller of 90% of this year’s tax or 100% of last year’s tax (110% if last year’s adjusted gross income was over $150,000).
Is Colorado’s safe harbor the same?
No. Colorado uses 70% of this year’s tax, or 100% of last year’s tax if last year’s federal adjusted gross income was $150,000 or less, otherwise 110%, according to the 2026 DR 0104EP worksheet.
When are 2026 payments due?
April 15, June 15 and September 15, 2026, and January 15, 2027, for both the IRS and Colorado.
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