Colorado's flat 4.4% income tax
Colorado taxes income at a flat 4.4%, whatever the amount and filing status. The Colorado standard deduction is $16,100 for single filers, $32,200 for married couples filing jointly and $24,150 for heads of household — the same amounts as the federal deduction.
This is Colorado's 2025 schedule, the latest the calculator has. It was checked on 2026-09-30 against Colorado DOR Individual Income Tax Guide (tax on modified federal taxable income; 4.4% for 2025); DR 1098 2026 withholding at 4.40%.
Some Colorado cities levy a flat monthly occupational privilege tax that is not included here.
Colorado and federal income tax by income
At the calculator's default $85,000, Colorado takes $3,032 of a $12,902 total income tax bill, or 23%. Filing status matters too: a married couple filing jointly on $170,000 owes Colorado $6,063 — exactly what two single filers earning $85,000 each would pay.
| Gross income | Colorado tax | Colorado rate | Federal tax | Combined effective rate |
|---|---|---|---|---|
| $30,000 | $612 | 2.04% | $1,420 | 6.77% |
| $50,000 | $1,492 | 2.98% | $3,820 | 10.62% |
| $65,000 | $2,152 | 3.31% | $5,620 | 11.96% |
| $85,000 (default) | $3,032 | 3.57% | $9,870 | 15.18% |
| $100,000 | $3,692 | 3.69% | $13,170 | 16.86% |
| $125,000 | $4,792 | 3.83% | $18,734 | 18.82% |
| $200,000 | $8,092 | 4.05% | $36,734 | 22.41% |
| $300,000 | $12,492 | 4.16% | $68,134 | 26.88% |
| $400,000 | $16,892 | 4.22% | $103,134 | 30.01% |
Marginal tax rate in Colorado
The next dollar a single filer earns above $85,000 is taxed at 26.4%: 22% federal and 4.4% by Colorado. Because Colorado's rate is flat, its share of a raise stays 4.4% at any income above the standard deduction.