Colorado Quarterly Tax Calculator
Calculate your estimated quarterly tax payments for federal and Colorado state taxes. Designed for self-employed individuals, freelancers, and independent contractors.
CO State Tax: Flat 4.4%
Quarterly Payment Amount
$6,411
Per quarter (4 remaining)
Annual Tax Breakdown
2026 Payment Schedule
Jan 1 - Mar 31
Due: April 15, 2026
$6,411
Apr 1 - May 31
Due: June 15, 2026
$6,411
Jun 1 - Aug 31
Due: September 15, 2026
$6,411
Sep 1 - Dec 31
Due: January 15, 2027
$6,411
Don't miss your quarterly payments!
The IRS may charge penalties and interest if you underpay or pay late. Consider setting up automatic payments or calendar reminders.
Colorado Quarterly Tax Highlights
Colorado has a flat 4.4% income tax rate
Simple flat rate makes calculation easy
Use Form 104EP for quarterly payments
State tax is 4.4% of federal taxable income with modifications
Colorado Quarterly Tax FAQ
What is Colorado's income tax rate?
Colorado has a flat 4.4% income tax rate. This applies to all income levels equally, making tax calculation straightforward for self-employed individuals.
How do I pay quarterly taxes in Colorado?
Use Colorado Form 104EP to make quarterly estimated tax payments. Payments are due April 15, June 15, September 15, and January 15.
Official References
This calculator uses current federal and Colorado tax rates and schedules:
- IRS Estimated Tax Guidelines
Federal quarterly tax requirements and Form 1040-ES
- Colorado Department of Revenue
Official Colorado tax authority
- IRS Self-Employment Tax
Social Security and Medicare tax information
This calculator provides estimates based on 2026 tax rates. Your actual tax liability may vary based on deductions, credits, and other factors. Consult a tax professional for personalized advice.