Colorado Quarterly Tax Estimator 2026
Estimate your Colorado quarterly estimated tax payments for 2026. Covers federal income tax, self-employment tax, and Colorado state income tax.
Colorado Tax Overview for Estimated Payments
Colorado has a flat income tax rate of 4.4% on all taxable income. Colorado's constitution requires a flat tax — not a graduated system — and the state has a unique taxpayer protection mechanism called TABOR (Taxpayer's Bill of Rights) that limits how much tax revenue the government can keep. When state revenue exceeds the TABOR cap, the surplus must be refunded to taxpayers via the Colorado Cashback program. In recent years, TABOR refunds have delivered hundreds of dollars back to Colorado residents. Colorado's standard deduction mirrors the federal amount ($16,100 for single filers in 2026), which is among the most generous state standard deductions and means a significant portion of income is sheltered before the 4.4% applies. No Colorado city charges a local income tax on wages.
Here's what a single Colorado filer keeps in 2026. On a $50,000 salary, take-home is approximately $40,673 per year ($3,389/month) — with state income tax costing $1,492. At $80,000, take-home is $61,766 ($5,147/month), with Colorado taking $2,812 in state tax. At $100,000, you keep $74,956 ($6,246/month), with $3,692 going to state taxes. At $150,000, take-home is $107,290 ($8,941/month), with the state taking $5,892. If you receive a TABOR refund in a given year, add that on top.
Compared to neighboring Utah (4.5% flat), Colorado's 4.4% rate is slightly better — saving about $250 per year at $100,000. Against New Mexico (up to 4.9% for most earners), Colorado saves approximately $400 per year at $100,000. Against Wyoming (no income tax), Colorado workers at $80,000 pay an additional $2,812 in state tax. The TABOR refund partially closes this gap in years when the state over-collects. Denver workers benefit from no city income tax, unlike cities in some neighboring states.
Watch out: Colorado's Proposition 116 reduced the income tax rate from 4.55% to 4.4%, and future ballot initiatives could lower it further or change the flat tax structure. TABOR refunds are not guaranteed — they depend on whether the state collects more than its allowable revenue cap in a given year. Don't build TABOR refunds into your paycheck budget. Also note that while Colorado cities don't charge income taxes, several charge various business and occupation taxes that affect self-employed individuals differently than employees.