Free Colorado Income Tax Calculator 2026 — Flat 4.4%

Enter your income, filing status, and deductions, and this calculator applies Colorado’s real 2026 flat rate of 4.4% on Colorado taxable income and the 2026 standard deduction to estimate your state tax, effective rate, and take-home pay. It runs entirely in your browser — your income is never typed into anyone’s server. Educational estimate only; it excludes federal tax, other credits, and local taxes.

How it works

The calculator subtracts pre-tax deductions and the standard deduction (or your itemized amount if larger) from gross income to get Colorado taxable income, then applies the flat 4.4% rate — every taxable dollar is taxed the same, with no brackets. Colorado is one of the few states whose standard deduction simply mirrors the federal amounts, so when the IRS raises its standard deduction for inflation, Colorado’s automatically follows. Colorado has no personal exemption amount, so the dependent count is informational only.

Everyday uses

• Colorado workers — estimate your state withholding and avoid an April surprise.
• New residents — see what the move costs you under Colorado’s flat tax before you relocate.
• Freelancers — rough out quarterly Colorado estimated payments (Form 104-EP).
• Job changers — compare offers by real take-home, not headline salary.
• Retirees — model how Colorado’s generous pension exclusions (not modeled here) can shrink the bill further.

Frequently asked questions

Why is Colorado’s rate flat instead of graduated?

Colorado’s constitution requires a single rate of tax on taxable income — voters approved lowering it to 4.4% — so your marginal and effective rates stay close together no matter how much you earn.

Why does Colorado’s standard deduction mirror the federal one?

Colorado’s tax code starts from federal adjusted gross income and adopts the federal standard deduction by reference, so inflation adjustments from the IRS flow straight into the state return — no separate state table needed.

What is TABOR and does it change my tax?

TABOR (the Taxpayer’s Bill of Rights) caps state revenue growth and triggers refunds to taxpayers in surplus years — historically paid out as flat checks rather than rate cuts. This calculator estimates your liability before any TABOR refund.

Is this tax advice?

No — it is an educational estimator using 2026 figures. Credits (including Colorado’s earned-income and property-tax credits), exclusions, and special income can change your real bill; a tax professional can advise on your situation.