Idaho Estimated Tax Payments Calculator

2026 rules

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

Your numbers

Filing status

Self-employment or business profit

W-2 wages

Other income (interest, dividends, gains, rental)

Idaho tax withheld from paychecks

Last year's Idaho 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

Idaho quarterly payment$697

Projected federal tax (incl. SE tax)$17,147
Projected Idaho tax$3,097
Idaho amount to pay in estimates$2,787
Idaho payment 1 · Apr 15, 2026$697
Idaho payment 2 · Jun 15, 2026$697
Idaho payment 3 · Sep 15, 2026$697
Idaho payment 4 · Jan 15, 2027$697
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$4,555

Idaho at a glance

Due dates: Apr 15, 2026, Jun 15, 2026, Sep 15, 2026, Jan 15, 2027
Rates: Idaho has a flat 5.30% income tax.

Idaho adjusts its brackets or deductions for inflation; the amounts shown are the latest published, which may be the 2025 figures.

Idaho tax brackets for 2026

Single (taxable income)
Rate	Taxable income
5.30%	over $4,811

Married filing jointly
Rate	Taxable income
5.30%	over $9,622

Questions

When are Idaho 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 Idaho estimated-tax instructions too.