Colorado income tax goes up to 4.4% at the top bracket. Calculate your combined federal + state effective tax rate for 2026. Formula shown, sources cited — no account required.
Colorado's flat 4.4% income tax rate applies to all taxable income above the personal exemption. The simplicity of a flat structure means median earners and high earners share the same marginal rate at the state level — which benefits higher-income households relative to states with steeply graduated rates. For a household earning $97,113, the state tax bill runs roughly $4,273 annually before deductions. Colorado closely conforms to the federal adjusted gross income base, so most federal deductions carry through. One notable Colorado-specific benefit is the pension and annuity income subtraction for taxpayers over 55, which reduces taxable retirement income below the flat tax threshold. At the combined federal and state level, a median Colorado earner typically faces an effective all-in rate in the 22–26% range depending on filing status. Use the tax bracket calculator to map your exact combined liability and understand which income thresholds matter for your financial planning.
Colorado Tax Brackets Explained (2026)
Colorado has a state income tax with a top marginal rate of 4.4%. On top of federal rates (10%–37%), residents can face a combined marginal rate exceeding 35% at higher income levels. However, your effective rate is always lower than the marginal rate because only income above each threshold is taxed at that bracket's rate.
The median household in Colorado earns $97,113/year. At that income (single filer), the federal effective rate is approximately 12–14%, bringing total income tax (federal + state) to roughly 15–17%.
How Marginal vs. Effective Rate Works
The marginal rate is the rate on your last dollar of income — it does not apply to all income. The effective rate is your total tax divided by total income. For example, someone earning $100,000 in Colorado has a 22% federal marginal rate but an effective federal rate of roughly 15%, because the first $44,725 (2024) is taxed at 10% and 12%, not 22%.