Colorado Capital Gains Tax Calculator - Estimate Colorado state tax on stock, crypto, and real estate gains at the flat 4.40% rate.

The Colorado Capital Gains Tax Calculator estimates the Colorado state income tax owed on capital gains from selling stocks, crypto, real estate, or other assets. You enter your federal adjusted gross income, the gain amount, and your deduction, and the tool applies Colorado's flat 4.40% rate. Use it before you file to see how a sale changes your Colorado Form 104 bill, to compare a sale across tax years, or to decide whether to realize a gain in the current year.

It is built for Colorado residents and part-year residents who want a quick, source-based estimate without climbing through brackets. Because Colorado is a flat-tax state, the calculator's main job is finding your Colorado taxable income rather than looking up a bracket. The result tells you the state tax on the gain itself and the total Colorado tax on your return.

Unlike states with graduated brackets, a larger gain in Colorado simply scales the 4.40% line, so the estimate stays predictable whether you sell $5,000 of stock or $500,000 of property. The Colorado Capital Gains Tax Calculator is a planning tool, not a substitute for the forms, but it shows the state dollars at stake before you act.

If you want the full-state picture from the same AGI, open the Colorado income tax calculator alongside it.

Colorado starts from your federal AGI, adds state additions, subtracts state subtractions, subtracts the larger of your standard or itemized deduction, and multiplies the positive remainder by 4.40%. Because the rate is flat, the capital gains portion is simply the gain times 4.40%. There is no separate long-term rate, no excluding of gains, and no additional local layer, so the only moving parts are your deduction and any state adjustments.

Worked example: a $20,000 long-term gain added to $75,000 AGI with a $15,750 single deduction gives $79,250 of Colorado taxable income. The gain adds $880 of state tax ($20,000 × 4.40%). The Colorado Department of Revenue confirms the flat 4.40% rate is applied to Colorado taxable income on Form 104, and IRS Publication 544 explains that gains are part of federal AGI.

The formula is:

To see how the federal layer feeds this, try the federal income tax calculator.

1. 1Enter your federal adjusted gross income from your draft federal return.
2. 2Enter your short-term and long-term capital gain separately if you have both.
3. 3Add any Colorado additions and subtractions you expect.
4. 4Choose your deduction (standard or itemized) for the tax year.
5. 5Select the tax year (2024, 2025, or 2026).
6. 6Read the Colorado tax on the gain and the total state tax estimate.

Practical example: a Colorado single filer with $75,000 AGI and a $20,000 long-term crypto gain enters those figures, keeps the $15,750 deduction, and reads about $880 of state tax on the gain.

• Shows the exact 4.40% state tax on a gain before you decide when to sell.
• Anchors the estimate to federal AGI so it matches your real filing base.
• Compares a sale across 2024-2026 without rerunning a federal calculator.
• Makes clear there is no surcharge, so large gains stay at 4.40%.
• Flags when a gain falls below the deduction floor and produces no state tax.
• Splits short- and long-term gains so you can test how a holding period change lands on your return.
• Handles Colorado additions and subtractions so retirement or other state adjustments are reflected, not just the federal number.

For wage income that builds your AGI, the Colorado paycheck calculator shows the withholding behind that number.

Per the Colorado Taxpayer Bill of Rights (TABOR), the rate is set by voter-approved statute, not by annual brackets, which is why the 4.40% figure holds steady while the federal brackets and the standard deduction amounts move underneath it. To contrast with a progressive state, the California capital gains tax calculator stacks gains onto brackets plus a surcharge.

A Colorado home sale still runs through the federal capital gains exclusion first. If you qualify for the $250,000 single or $500,000 married exclusion on your primary residence, that excluded amount never reaches federal AGI, so Colorado never sees it either. The taxable portion of the gain does flow into AGI and is taxed at 4.40% just like any other gain.

Rental and investment property is different: depreciation you claimed lowers your cost basis and shows up as federal gain, and Colorado follows that same basis. The U.S. capital gains tax calculator shows the federal side of that disposition if your sale also produces rental income or suspended losses.

Crypto trades are taxed the same way. Each swap, sale, or spend is a disposition reported on your federal return, and the resulting gain enters federal AGI at 4.40% on the Colorado side. Because the rate is flat, a large one-year crypto gain does not push you into a higher bracket the way it can on the federal return.

Colorado's 4.40% flat rate makes it one of the simpler states for gain planning. A progressive state such as California layers gains onto brackets and adds a 1% mental-health surcharge above $1 million, so a large gain can cost far more than in Colorado. An Arkansas capital gains tax calculator uses a low flat rate but still differs from Colorado's structure and is worth checking side by side.

Because Colorado has no local income tax, the 4.40% you calculate here is the whole state bill on the gain; there is no city or county layer to add.

A Colorado married couple has $120,000 of federal AGI from wages and sells stock for a $15,000 short-term gain and a $35,000 long-term gain. They take the 2025 married standard deduction of $31,500.

Colorado taxable income = $120,000 + $50,000 gain − $31,500 = $138,500. Total Colorado tax = $138,500 × 4.40% = $6,094. The tax tied to the $50,000 gain alone is $2,200.

This is exactly what the Colorado Capital Gains Tax Calculator reports when you enter those numbers, and it shows why a flat rate keeps the math linear: double the gain, double the Colorado tax on it.

Colorado Form 104 is due the same day as your federal return, generally April 15. You report the gain on your federal Form 1040 Schedule D, and Colorado begins with the AGI that results. Estimated payments during the year should account for a large planned gain so you are not surprised at filing.

Part-year residents apportion income to the time they lived in Colorado; the calculator assumes full-year Colorado residency, so adjust your AGI if you moved mid-year. Nonresidents with Colorado-source gains follow a different apportionment.

If you also have wage income, your employer withholding builds the AGI side of this estimate, and the year-end numbers should reconcile with what you enter above.