Income Tax for Colorado (2026)

How This Calculator Works in Colorado

This calculator applies Colorado's 2026 tax brackets and rates to estimate your state income tax liability. Enter your income and filing status to see your marginal rate, effective rate, and estimated tax owed.

Colorado Overview

Colorado levies a flat income tax of 4.4%, recently reduced from 4.55% by voter-approved Proposition 121. The state's TABOR amendment (Taxpayer's Bill of Rights) uniquely limits revenue growth and requires refunds when collections exceed the cap — Colorado is the only state with this mechanism. Colorado uses federal taxable income as the starting point for state tax calculations, simplifying filing for most residents.

How Colorado Compares

Colorado's top income tax rate of 4.4% compares to Utah at 4.65% and New Mexico at 5.9%. The rate differences can meaningfully impact take-home pay for workers near state borders.

Colorado's income tax rate of 4.4% compares to a national average of approximately 5.04%. This is below the national average.

Tips for Colorado Residents

• 1Colorado has a flat income tax rate of 4.4%, reduced from 4.55% effective January 2024 through voter-approved Proposition 121.
• 2TABOR (Taxpayer's Bill of Rights) limits the state's ability to raise taxes without voter approval and requires refunds when revenue exceeds constitutional limits.
• 3When TABOR refunds are triggered, every Colorado taxpayer receives a check or credit — the amount varies year to year and is typically $400-$800 per adult.
• 4Colorado uses federal taxable income as the starting point for your state return, so most federal deductions and adjustments flow through automatically.
• 5If you own a home, the Property Tax, Rent, and Heat (PTC) Rebate provides additional relief for lower-income and senior residents.

Frequently Asked Questions