How Montana income tax works
Montana taxes individual income with 2 brackets ranging from 4.70% to 5.90%.
Your tax is calculated on taxable income — gross income minus the $14,600 standard deduction for a single filer.
Two brackets of 4.7% and 5.9% after recent simplification.
Montana income tax rates for 2026
Only the income that falls inside each bracket is taxed at that bracket's rate — this is how marginal tax works, so your effective rate is always lower than your top bracket.
Your effective rate is the total tax divided by your gross income; your marginal rate is the rate on your next dollar earned. The calculator shows both.
Montana taxes long-term capital gains at reduced rates of 3.0% or 4.1%.
Lowering your Montana tax bill
Pre-tax contributions to retirement accounts, health savings accounts and other deductions reduce the taxable income this calculator starts from.
Remember this estimate covers MT state income tax only. Federal income tax and payroll taxes apply on top, and this is a planning estimate — verify with the Montana Department of Revenue (mtrevenue.gov) or a tax professional.
Frequently asked questions
How much is Montana state income tax?
Montana uses progressive brackets from 4.70% to 5.90%.
What is the difference between effective and marginal rate?
Your marginal rate is the rate on your last dollar of income; your effective rate is your total tax divided by total income, which is lower because of brackets and deductions.
Does this include federal tax?
No. This calculator estimates MT state income tax only. Federal income tax and payroll taxes are separate and apply on top.
How are capital gains taxed in Montana?
Montana taxes long-term capital gains at reduced rates of 3.0% or 4.1%.