Montana Capital Gains Tax Calculator
Calculate capital gains tax in Montana. State rate: 5.65%. See federal + state combined tax on stocks, property, and investments.
Estimate only — these are not official figures
Modeled estimate. Federal regular tax uses official 2026 IRS ordinary and long-term brackets, but assumes the entered transaction is a net gain eligible for the general rates and omits collectibles, unrecaptured section 1250 gain, section 1202 stock, home-sale exclusions, transaction costs, other gains/losses, and AMT. NIIT uses the entered MAGI and net-investment-income proxies. State tax is not a return calculation: Montana taxes long-term capital gains (assets held more than one year) on a separate preferential schedule under Mont. Code Ann. §15-30-2103(2): 3.0% on the first $95,000 of net long-term capital gain for single filers ($71,250 head-of-household, $47,500 married-filing-separately/jointly) and 4.1% above that threshold; this displayed default models only the 4.1% top long-term tier. Short-term gains remain taxed at Montana's ordinary graduated rate (5.65% top bracket) shown elsewhere on this page. Montana does not offer a capital-gains tax credit; that description was incorrect. The 2024 breakpoints above apply through tax year 2026; a 2027 law change raises them to $130,000 (single) / $97,500 (HOH/MFS/MFJ).
Do not rely on these amounts for budgeting or payment. For exact amounts, check the Montana tax authority (https://mtrevenue.gov/taxes/individual-income-tax/) and IRS Topic 409 (https://www.irs.gov/taxtopics/tc409), Rev. Proc. 2025-32 (https://www.irs.gov/pub/irs-drop/rp-25-32.pdf), and NIIT guidance (https://www.irs.gov/individuals/net-investment-income-tax).
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Additional Details
Pre-filled: Editable top/representative-rate proxy; not a state return calculation
Additional Details
Estimated Federal + State Tax
Estimated • Based on your inputs
Estimated Net Sale Proceeds
$90,450.00
Detailed Breakdown
Disclaimer: This calculator provides estimates for informational purposes only. Results should not be considered financial, tax, or legal advice. Consult a qualified professional for your specific situation.
How This Calculator Works
Calculation methodology and assumptions
This planning estimate subtracts purchase basis and entered positive basis adjustments from sale proceeds, floors losses at $0, and classifies 13+ entered whole months as long-term because IRS rules require more than one year. General long-term gain is stacked over other federal taxable income through the official 2026 0%/15%/20% brackets; short-term gain is the incremental tax through the official 2026 ordinary brackets for the selected filing status. Incremental NIIT is 3.8% of the lesser-of calculation using entered MAGI and net investment income before and after the gain. State tax is only modeled gain multiplied by an editable flat proxy. It does not prepare Schedule D, Form 8949, Form 8960, or a Montana return, and it omits losses, selling costs unless netted into proceeds, special federal gain categories, exclusions, AMT, and state-specific computations described below.
Key State Information
Montana taxes long-term capital gains (assets held more than one year) on a separate preferential schedule under Mont. Code Ann. §15-30-2103(2): 3.0% on the first $95,000 of net long-term capital gain for single filers ($71,250 head-of-household, $47,500 married-filing-separately/jointly) and 4.1% above that threshold; this displayed default models only the 4.1% top long-term tier. Short-term gains remain taxed at Montana's ordinary graduated rate (5.65% top bracket) shown elsewhere on this page. Montana does not offer a capital-gains tax credit; that description was incorrect. The 2024 breakpoints above apply through tax year 2026; a 2027 law change raises them to $130,000 (single) / $97,500 (HOH/MFS/MFJ). Short- and long-term federal treatment is calculated separately, but the state estimate applies the displayed 4.1% proxy to either holding period.
Example Calculation
How much tax do you owe on a $50,000 capital gain in Montana?
You bought stock for $100,000 and sold it for $150,000 after holding for 2 years. In this simplified illustration, the full $50,000 long-term gain is in the 15% federal band, producing $7,500 of regular federal tax before NIIT. Applying the calculator's editable 5.65% Montana state-rate proxy adds $2,825; that proxy is not a state return calculation.
Result: This simplified illustration totals approximately $10,325 (20.6% of gain) using the Montana proxy. Actual results can cross federal brackets and depend on NIIT, losses, asset type, and state-specific rules.
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StateCalc Team
Editorial Team
The StateCalc team builds free financial calculators using data from official government sources including the IRS, U.S. Census Bureau, BLS, and state revenue departments. All formulas are validated by an automated test suite and cross-referenced against published data.
Our editorial standardsFrequently Asked Questions
What is the capital gains tax rate in Montana?
There is not one rate that is correct for every Montana sale. This calculator starts with an editable 4.1% state proxy, then applies it flat to the modeled gain. Montana taxes long-term capital gains (assets held more than one year) on a separate preferential schedule under Mont. Code Ann. §15-30-2103(2): 3.0% on the first $95,000 of net long-term capital gain for single filers ($71,250 head-of-household, $47,500 married-filing-separately/jointly) and 4.1% above that threshold; this displayed default models only the 4.1% top long-term tier. Short-term gains remain taxed at Montana's ordinary graduated rate (5.65% top bracket) shown elsewhere on this page. Montana does not offer a capital-gains tax credit; that description was incorrect. The 2024 breakpoints above apply through tax year 2026; a 2027 law change raises them to $130,000 (single) / $97,500 (HOH/MFS/MFJ).
Does Montana tax short- and long-term capital gains differently?
Montana taxes long-term capital gains (assets held more than one year) on a separate preferential schedule under Mont. Code Ann. §15-30-2103(2): 3.0% on the first $95,000 of net long-term capital gain for single filers ($71,250 head-of-household, $47,500 married-filing-separately/jointly) and 4.1% above that threshold; this displayed default models only the 4.1% top long-term tier. Short-term gains remain taxed at Montana's ordinary graduated rate (5.65% top bracket) shown elsewhere on this page. Montana does not offer a capital-gains tax credit; that description was incorrect. The 2024 breakpoints above apply through tax year 2026; a 2027 law change raises them to $130,000 (single) / $97,500 (HOH/MFS/MFJ).
How is federal capital-gains tax estimated?
For general long-term gain, the calculator stacks the gain above your other taxable income through the 2026 0%, 15%, and 20% brackets. For short-term gain, it computes the increase through the selected filing status’s ordinary brackets. NIIT is a separate incremental lesser-of calculation. Special rates for collectibles, unrecaptured section 1250 gain, and section 1202 stock are not included.
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