State income tax
Colorado state income tax: 4.4% flat rate
Colorado taxes wages at a flat 4.4% — the same rate on every dollar of taxable income.
Quick answer
Current colorado state income tax: 4.4% flat rate rules and rates by state, with the calculator to apply them to your own numbers.
Reviewed by BoringToolsKit · August 26, 2026 · This state's rate verified 2026-09-12 against the state's own document: tax.colorado.gov DR 0104EP (2026) - 'Estimated 2026 Colorado income tax - 4.4%'. Simplified illustration for a single filer — excludes the standard deduction, exemptions, credits, and any local/city income taxes, and real state rules differ (married-filer brackets, phase-outs, inflation indexing). Rules change year to year; verify with the state revenue department. Informational, not tax advice.
How Colorado taxes income
A flat-rate state taxes every dollar of taxable income at the same percentage, so the marginal rate equals the effective rate before deductions. Colorado’s flat rate is 4.4%.
Run your numbers
$80,000 single filer in Colorado
Graduated brackets tax only the income inside each band. On $80,000, Colorado taxes each slice like this:
| Rate | Starts at | Taxed amount | Tax |
|---|---|---|---|
| 4.4% | $0 | $80,000 | $3,520 |
| Total | $3,520 |
Marginal rate 4.4% · effective rate 4.40% — the last dollar is taxed at the marginal rate, but the whole income averages to the effective rate.
| Rate | Single-filer taxable income |
|---|---|
| 4.4% | All income |
Single-filer tax at common incomes
Estimated state income tax before deductions and credits:
| Income | Tax | Effective rate |
|---|---|---|
| $50,000 | $2,200 | 4.40% |
| $100,000 | $4,400 | 4.40% |
| $150,000 | $6,600 | 4.40% |
Simplified illustration for a single filer — excludes the standard deduction, exemptions, credits, and any local/city income taxes, and real state rules differ (married-filer brackets, phase-outs, inflation indexing). Rules change year to year; verify with the state revenue department. Informational, not tax advice.
State income tax questions, answered
What is the difference between marginal and effective state income tax?
Your marginal rate taxes only the last dollar of income; your effective rate is total state tax divided by total income. In a graduated state most filers’ effective rate is well below the top marginal rate.
Does Colorado tax all income at the top rate?
No. Graduated brackets tax only the income inside each band, so the rate you see on the last dollar is not the rate on the first dollar.
Which states have no individual income tax?
Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming collect no state individual income tax on wages.
Is this calculator tax advice?
No — this is a simplified illustration for a single filer that excludes the standard deduction, exemptions, credits, and local/city taxes. Verify with the state revenue department.
Put the rate to work
See the state income tax comparison table, the full bracket index, or the salary-to-hourly converter.