Colorado Quarterly Estimated Tax Calculator 2026
Colorado has a flat income tax rate of 4.4%, which is included in your quarterly payment calculation. Use this calculator to estimate your quarterly tax payments including self-employment tax and federal income tax plus Colorado state income tax.
Your 2026 Quarterly Payments — Colorado
Total Annual Tax
$0
Per Quarter
$0
Take Home
$0
Effective Rate
0%
Tax Breakdown
Quarterly Estimated Taxes in Colorado
As a self-employed worker in Colorado, your quarterly estimated tax payments need to cover three components: federal self-employment tax (15.3% on 92.35% of net earnings), federal income tax, and Colorado state income tax. Colorado has a flat income tax rate of 4.4%, which is included in your quarterly payment calculation.
State note: Colorado uses federal AGI as the starting point for state taxes.
Does Colorado Require Separate State Quarterly Payments?
Most states with income tax, including Colorado, require their own separate quarterly estimated tax payments if you expect to owe state income tax. Check your state's tax authority website for state-specific forms and due dates, which may differ from federal deadlines.
2026 Federal Quarterly Due Dates
Regardless of which state you're in, the federal quarterly estimated tax due dates for 2026 are: Q1 — April 15, Q2 — June 15, Q3 — September 15, and Q4 — January 15, 2027. Payments are made using Form 1040-ES and can be submitted via IRS Direct Pay, EFTPS, or by mail.
Other States
No Income Tax States
Colorado Tax Quick Facts
- Income Tax
- Yes
- Tax Type
- flat
- Rate
- 4.40%
- SE Tax Rate
- 15.3%
- SS Wage Base
- $176,100