Taxes

Idaho Income Tax Explained (2026)

Idaho has a flat 5.3% income tax (down from 5.695%), with a federal-sized deduction. How the low flat rate works on a paycheck. Free Idaho calculator inside.

By FinanceTool Editorial Team · Published June 13, 2026 · 5 min read

The Boise, Idaho skyline at golden hour with the foothills and Boise River.

Idaho charges a flat 5.3% income tax, so every worker pays the same rate regardless of income. The state recently consolidated its old graduated brackets and has been cutting the flat rate (it was 5.695% as recently as 2022).

With a flat rate and a federal-sized standard deduction, Idaho is simple to estimate. Here is how it works on your paycheck. See your exact take-home with the free Idaho paycheck calculator.

How Idaho's income tax works

Idaho applies a single 5.3% rate (2025) to your taxable income, using a standard deduction equal to the federal amount. There are no brackets to climb and no local income tax, so your state tax is easy to predict at any salary.

Idaho has steadily lowered this rate in recent years, from a graduated system down to 5.8%, then 5.695%, and now 5.3%, so the state portion has been shrinking.

Your take-home on a $65,000 salary in Idaho

Here is how a $65,000 salary breaks down for a single filer, using 2025 federal and FICA figures alongside Idaho's a flat 5.3% income tax.

ItemAnnual
Federal income tax$5,246
FICA (Social Security + Medicare)$4,973
Idaho income tax$2,650
Take-home pay$52,132
Percent of gross kept80.2%

On a $65,000 salary a single filer owes about $2,650 in Idaho income tax, an effective rate near 4.1% after the standard deduction, and keeps roughly $52,132, or 80.2% of gross. In fast-growing Boise and the surrounding Treasure Valley, that take-home now contends with housing costs that have risen sharply as new residents arrive. Compare with Utah.

A flat rate that keeps getting cut

Idaho's story is its rapid move to a low flat tax: it collapsed graduated brackets into a single rate and has trimmed it repeatedly, landing at 5.3% for 2025. The practical effect is a simple, moderate bill that is the same percentage for every earner.

Idaho does not tax Social Security and offers deductions for some retirement income, so retirees generally pay below the flat rate that applies to wages.

How to keep more of your Idaho paycheck

Because Idaho applies its flat rate to a federal-style base, a traditional 401(k) and HSA lower your Idaho and federal taxable income together (and the HSA also avoids FICA), the cleanest way to nudge your take-home higher.

Frequently asked questions

Sources & methodology: The Idaho State Tax Commission and the Tax Foundation. Figures use 2025 state rules with 2025 federal and FICA amounts.