What is the colorado income tax calculator?
In short
Colorado taxes all taxable income at a flat 4.40% income tax — a single flat rate rather than progressive brackets, so a higher salary doesn't push you into a higher state rate. A single filer earning $75,000 in Colorado owes about $15,999 all-in ($2,592 to the state), taking home $59,001.
This Colorado income tax calculator estimates your total tax — federal brackets + FICA (7.65%) + Colorado's a flat 4.4% income tax. Colorado's flat rate can move down temporarily in surplus years under TABOR (the Taxpayer's Bill of Rights), so the effective rate varies by tax year — 4.25% in 2024, 4.40% in 2025.
How to use this calculator
- 1Enter your annual gross income.
- 2Choose your filing status (single, married, or head of household).
- 3Colorado is pre-selected — switch states to compare.
- 4Enter pre-tax deductions (401k, HSA) and any itemized deductions.
- 5Read your federal tax, state tax, FICA, total, and effective rate.
The formula
- AGI
- — Gross income minus pre-tax deductions
- taxable income
- — AGI minus the standard or itemized deduction
- federal tax
- — Federal income tax from progressive brackets
- CO tax
- — Colorado — a flat 4.40% income tax
- FICA
- — Social Security 6.2% + Medicare 1.45%
Worked example
The scenario
Single filer earning $75,000 in Colorado, standard deduction.
The result
Federal ~$7,670, Colorado state ~$2,592 (4.4% flat), FICA ~$5,738 → total ~$15,999, take-home $59,001 (21.3% effective).
Common use cases
- Estimating your total tax bill before filing in Colorado
- Comparing Colorado's flat 4.4% rate against progressive-bracket states
- Seeing how pre-tax 401(k)/HSA contributions lower your tax
- colorado bases state taxable income on federal taxable income, so it keeps no standard deduction of its own
Limitations & assumptions
- Local/city income taxes aren't included; Colorado applies its 4.4% rate statewide.
- Rates change: The statutory rate is 4.40%, but Colorado's TABOR surplus mechanism can temporarily lower it — it dropped to 4.25% for tax year 2024, then reverted to 4.40% for 2025.
- Federal calculation uses current brackets and the standard deduction unless you itemize.
- Use it for planning; it isn't a substitute for a tax professional.
Frequently asked questions
What is the Colorado state income tax rate?
How much is $75,000 taxed in Colorado?
Does Colorado have a standard deduction?
How much is $100,000 taxed in Colorado?
Is Colorado's income tax going down?
Disclaimer: KalkWise calculators are provided for general informational and educational purposes only and do not constitute financial, investment, tax, or legal advice. Results are estimates based on the figures you enter and the assumptions described above. Actual outcomes will vary. Consult a qualified professional before making financial decisions.