What is Colorado's income tax rate for 2024?

Colorado has a single flat income tax rate of 4.40% for the 2024 tax year. There are no graduated brackets — every dollar of Colorado taxable income is taxed at the same rate, regardless of how much you earn.

How is Colorado taxable income calculated?

Colorado taxable income starts from your federal taxable income, then adds state-specific additions and removes Colorado subtractions such as the pension and annuity subtraction or interest on US government bonds. The flat 4.40% rate is applied to that adjusted figure.

Does Colorado have a standard deduction?

Colorado does not have its own standard deduction. Because Colorado taxable income begins with federal taxable income, your federal standard or itemized deduction has already been removed before Colorado's rate is applied. This calculator can subtract the federal standard deduction for you if you enter AGI.

What are TABOR refunds?

Under the Taxpayer's Bill of Rights, when state revenue exceeds a constitutional cap, the surplus is refunded to taxpayers. In some years TABOR has temporarily lowered the effective income tax rate or sent flat-dollar refunds, so your net cost can be below the headline 4.40%.

Is this calculator a substitute for filing software?

No. It is a fast planning estimate of your Colorado state income tax. It does not capture every addition, subtraction, or refundable credit on Form DR 0104, nor TABOR adjustments for a specific year. Use it to budget, then file with official software or a preparer.

Colorado Income Tax Calculator

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The Colorado income tax calculator applies the state’s flat 4.40% rate to your taxable income and shows your effective rate after subtractions and credits. Because Colorado has no brackets, the result is precise and easy to reason about.

How it works

Colorado is one of a handful of true flat-tax states. The calculation is:

Start from federal taxable income. If you only know your AGI, the tool subtracts the federal standard deduction for your filing status to get there.
Apply Colorado subtractions. Items like the pension/annuity subtraction, interest on US government obligations, and certain capital-gain subtractions reduce your Colorado taxable income.
Apply the flat rate. Multiply Colorado taxable income by 4.40%.
Subtract nonrefundable credits such as the child care expenses credit.

The result is your Colorado income tax, shown alongside your effective rate (tax ÷ income).

Worked example

A single filer with $60,000 AGI and no subtractions:

Federal taxable income: $60,000 − $14,600 standard deduction = $45,400
Colorado tax: $45,400 × 4.40% = $1,997.60
Effective rate on AGI: about 3.33%

Add a $5,000 pension subtraction and the taxable base falls to $40,400, cutting the tax to about $1,777.60.

Notes and tips

Because the rate is flat, your marginal rate always equals 4.40% — every extra dollar of Colorado taxable income costs the same.
Watch for TABOR years: a voter-mandated surplus refund can effectively lower what you owe below the headline rate.
This tool isolates the state income tax. Pair it with the Colorado paycheck calculator to see how the flat tax interacts with federal withholding and FICA.