Estimate your Colorado state income tax plus combined federal and CO state tax for 2026. 4.4% flat rate.
Colorado has a flat income tax rate of 4.4% on all taxable income. Colorado's TABOR (Taxpayer's Bill of Rights) limits state revenue growth and can result in refunds to taxpayers. Colorado recently reduced its flat rate from 4.55%. Use the calculator above to estimate your combined federal and Colorado state income tax for 2026. State tax figures use a simplified rate — for precise Colorado state tax calculations, consult the Colorado Department of Revenue or a licensed tax professional.
Colorado uses a 4.4% flat rate state income tax structure. Like most states, Colorado starts its calculation from your federal Adjusted Gross Income (AGI), then applies state-specific adjustments — subtracting income Colorado excludes from taxation (such as certain pension or Social Security income) and adding back any income Colorado taxes that the federal government does not. After adjustments, the Colorado standard deduction is applied, then the 4.4% flat rate is applied to arrive at state taxable income.
Colorado income tax is collected through employer paycheck withholding for W-2 employees and through quarterly estimated payments for self-employed residents and those with significant non-wage income. The Colorado state return is generally due April 15, aligned with federal returns. Part-year residents and nonresidents who earn income sourced in Colorado must also file a Colorado return for that income portion.
Your Colorado state income taxes are deductible on your federal Schedule A as part of the SALT (State and Local Tax) deduction, capped at $40,400 in 2026 under OBBBA. At the 22% federal bracket, paying $2,607 in Colorado state income tax generates approximately $573 in federal tax savings, reducing the true net cost of your Colorado taxes to about $2,034 for itemizing taxpayers.
Jordan is a single filer earning $75,000 in Colorado. This shows how federal and Colorado state income tax are calculated together.
Moving to a no-income-tax state (Texas, Florida, Nevada, or Wyoming) would save Jordan approximately $2,607/year ($217/month) in state income taxes. However, no-income-tax states often fund services through higher property taxes, sales taxes, or other fees, so a complete comparison requires evaluating all taxes together, not just income tax.
Colorado Tax Rate and Annual Filing
Colorado residents earning above the state filing threshold must file a Colorado income tax return annually, typically due April 15. The 4.4% flat rate applies after Colorado-specific deductions and any state tax credits. Employers withhold Colorado state income tax from employee paychecks throughout the year using Colorado withholding tables, and any balance owed or refund due is settled when the annual state return is filed. Self-employed Colorado residents make quarterly estimated payments to the state in addition to their federal quarterly estimated tax payments.
Federal SALT Deduction Reduces Net State Tax Cost
State income taxes paid in Colorado reduce your federal taxable income through the SALT deduction (capped at $40,400 in 2026 under OBBBA). For a Colorado resident in the 22% federal bracket paying $2,607 in state income tax, the SALT deduction recovers approximately $573 in federal taxes, so the true after-federal-benefit cost of Colorado state income tax is about $2,034. This offset only benefits taxpayers who itemize deductions on federal Schedule A rather than taking the standard deduction.
Total Tax Burden: State Income Tax Is One Piece
State income tax is one component of your total tax burden in Colorado. Property taxes, local income taxes (in some Colorado cities and counties), and state and local sales taxes also contribute to your overall cost of living. When comparing Colorado to other states, evaluate all tax types together rather than income tax in isolation. Use the calculator above to see your combined federal and Colorado state effective rate at your specific income level.
Sponsored
E-file.com offers the same features as TurboTax and H&R Block at half the price. Free federal filing available if you qualify. 40% cheaper than the big names.
File Your Taxes Now →We earn a commission if you file through this link at no extra cost to you.
Colorado has a 4.4% flat rate state income tax for 2026. Colorado has a flat income tax rate of 4.4% on all taxable income. Colorado's TABOR (Taxpayer's Bill of Rights) limits state revenue growth and can result in refunds to taxpayers. Colorado recently reduced its flat rate from 4.55%. The state income tax is calculated separately from federal income tax and is paid through payroll withholding or quarterly estimated payments.
Colorado has its own state standard deduction separate from the federal standard deduction ($15,750 single, $31,500 MFJ in 2026). For precise Colorado state deduction amounts, consult the Colorado Department of Revenue or a state tax professional.
Colorado's 4.4% flat rate state income tax can be compared to other states using our state tax calculator above. The U.S. average top marginal state income tax rate is approximately 5-6%. Nine states have no income tax at all (Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, Wyoming), while California has the highest at 13.3%.
Colorado offers state tax credits and deductions that may reduce your state tax liability. Common state credits include earned income credits, child tax credits, and credits for the elderly. Consult the Colorado Department of Revenue website or a licensed tax professional for credits specific to your situation and income level.
Use the calculator above. Enter your income and CO is pre-selected as your state. The calculator computes your 2026 federal income tax using the One Big Beautiful Bill Act brackets (10%-37%), adds your estimated Colorado state income tax (4.4% flat rate simplified), and displays your total tax burden, combined effective rate, and annual take-home pay. All calculations happen instantly in your browser.