Montana Estimated Tax Payments Calculator

2026 rules

Enter your expected income to see what to send Montana and the IRS each quarter.

Your numbers

Filing status

Self-employment or business profit

W-2 wages

Other income (interest, dividends, gains, rental)

Montana tax withheld from paychecks

Last year's Montana tax (total on your return)

Leave at 0 to use this year's estimate only.

Federal tax withheld

Last year's federal tax (Form 1040 line 24)

Result

Montana quarterly payment$703

Projected federal tax (incl. SE tax)$17,147
Projected Montana tax$3,122
Montana amount to pay in estimates$2,810
Montana payment 1 · Apr 15, 2026$703
Montana payment 2 · Jun 15, 2026$703
Montana payment 3 · Sep 15, 2026$703
Montana payment 4 · Jan 15, 2027$703
Federal amount to pay in estimates$15,433
Federal payment · Apr 15, 2026$3,858
Federal payment · Jun 15, 2026$3,858
Federal payment · Sep 15, 2026$3,858
Federal payment · Jan 15, 2027$3,858
First payment, state and federal$4,561

Montana at a glance

Due dates: Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Jan 15, 2027
Rates: Montana taxes income at 2 rates from 4.70% to 5.65%.

Montana tax brackets for 2026

Single (taxable income)
Rate	Taxable income
4.70%	$0 – $47,500
5.65%	over $47,500

Married filing jointly
Rate	Taxable income
4.70%	$0 – $95,000
5.65%	over $95,000

Questions

When are Montana estimated tax payments due for 2026?

Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Jan 15, 2027.

How much do I need to pay to avoid a penalty?

This calculator uses the federal safe harbor: 90% of this year's tax, or 100% of last year's (110% if your AGI is over $150,000), less withholding. A few states use a different share of the current year's tax, so check the Montana estimated-tax instructions too.