Montana State Income Tax Calculator
Estimate your state income tax bill by filing status.
This is a simplified estimate of Montana state income tax based on published bracket rates — it does not account for state-specific standard deductions, exemptions, or credits, which vary by state and filing status.
Montana income tax
How Montana taxes income
Montana uses a progressive income tax with rates that rise with income, topping out at 5.65% for the highest bracket.
Montana generally taxes retirement income such as pensions and 401(k)/IRA withdrawals, though specific exemptions can apply — check with a tax professional for your situation.
Frequently asked questions
What's the difference between marginal and effective tax rate?+
Your marginal rate is the rate applied to your last dollar of income (the top bracket you reach). Your effective rate is your total tax divided by total income — usually lower than your marginal rate under a progressive system.
Does this include deductions and credits?+
This calculator applies published bracket rates to your taxable income but doesn't model state-specific standard deductions, exemptions, or credits, which can meaningfully lower your actual bill.
How much state income tax on $75,000 in Montana?+
On $75,000 of taxable income in Montana, estimated state income tax is about $3,786 — a 5.0% effective rate and a 5.7% marginal rate on the last dollar earned.