What is the Idaho state income tax rate for 2025 and 2026?

Idaho has a flat 5.3% state income tax rate for 2026. This is a reduction from 5.695% in 2024 and 5.8% in 2023, continuing Idaho's trend of annual rate cuts since simplifying to a flat structure in 2023. The rate applies to all Idaho taxable income after deducting the standard deduction — there are no brackets and no higher rate at upper incomes.

What is the Idaho standard deduction for 2026?

Idaho uses the same standard deduction amounts as the federal government: $14,600 for single filers, $29,200 for married filing jointly, $21,900 for head of household, and $14,600 for married filing separately in 2026. This is considerably more generous than most state standard deductions — for example, Kansas allows only $3,500 (single) and Hawaii only $2,200 (single). A higher standard deduction means less income is exposed to the state rate.

Does Idaho recognize 401(k) pre-tax contributions?

Yes. Idaho fully recognizes traditional 401(k), 403(b), and IRA pre-tax contributions — they reduce Idaho taxable income exactly as they reduce federal taxable income. At 5.3%, maxing a 401(k) at $23,500 saves roughly $1,246 in Idaho state tax on top of federal savings. This stacks favorably for Idahoans who can contribute to employer retirement plans.

How much annual income tax does a $90,000 Idaho single filer owe?

A single filer earning $90,000 in Idaho in 2026 owes approximately: $12,140 in federal income tax (after $16,100 federal standard deduction), $6,885 in FICA, and about $4,005 in Idaho state tax (5.3% × ($90,000 − $14,600) = $4,005). Total taxes: roughly $23,030, an effective total rate of about 25.6% of gross income.

How is Idaho income tax changing in coming years?

Idaho has been on a multi-year schedule of income tax reductions. The rate was 6.5% before 2021, 5.8% in 2023 after switching to a flat structure, 5.695% in 2024, and 5.3% in 2026. The Idaho Legislature has generally favored continued reductions, though future rates depend on fiscal conditions and legislative decisions each year.

How is the annual income tax calculator different from the paycheck calculator?

This calculator estimates your full-year annual tax liability — federal plus Idaho state combined for the whole year — useful for tax planning, comparing states, and estimating what you owe at filing time. The paycheck calculator shows per-paycheck withholding and take-home pay frequency. Use both together for a complete picture of your Idaho tax burden.

Idaho Income Tax Calculator 2025 & 2026

Estimates Idaho state income tax (flat 5.3%), federal income tax, and FICA for 2025 and 2026 — flat rate, federal-equivalent standard deduction.

How to Use This Idaho Income Tax Calculator

This Idaho income tax calculator estimates your annual ID state and federal tax liability for 2025 and 2026. Enter your gross wages, filing status, and any deductions above. Idaho applies a flat 5.3% rate after the state standard deduction — identical in amount to the federal standard deduction. For per-paycheck withholding estimates, use the Idaho paycheck calculator.

How Idaho State Income Tax Works

Idaho simplified its income tax structure in 2023, moving from a multi-bracket progressive system to a single flat rate. The flat rate has been reduced each year since:

2023: 5.8%
2024: 5.695%
2026: 5.3%

The flat structure means every Idaho taxpayer pays the same marginal rate, regardless of income. A $40,000 earner and a $400,000 earner both pay 5.3% on their taxable income above the standard deduction. There are no brackets, no phase-outs, and no surtaxes.

Idaho's standard deduction matches the federal amounts — $14,600 for single filers and $29,200 for married filing jointly in 2026. This is among the most generous in the country; by comparison, Kansas allows only $3,500 (single) and Hawaii only $2,200 (single).

AdvertisementResponsive Ad

Step-by-Step Example — $90,000 Idaho Single Filer (2026)

Full annual tax calculation for a single Idaho resident earning $90,000:

Gross wages: $90,000
Federal standard deduction: −$16,100 → federal taxable income: $73,900
Federal income tax (10%–22% brackets): ≈ $12,140
FICA: $90,000 × 7.65% = $6,885
Idaho standard deduction: −$14,600 → Idaho taxable income: $75,400
Idaho income tax at 5.3%: $75,400 × 0.053 = $3,996
Total taxes: $12,140 + $6,885 + $3,996 = $23,021
Annual net income: $90,000 − $23,021 = $66,979

Idaho vs Neighboring States

Idaho sits among a mixed group of neighbors for state income tax. Washington and Nevada levy no state income tax. Utah has a comparable 4.65% flat rate. Oregon is significantly higher with progressive brackets reaching 9.9% for higher earners. A $90,000 single filer pays roughly $4,000 in Idaho state tax vs. about $7,400 in Oregon. Idaho's standard deduction also compares favorably — the $14,600 single deduction is roughly 6× larger than Kansas's $3,500. Use the general income tax calculator to compare Idaho with any other state side by side.

AdvertisementResponsive Ad

How to Reduce Your Idaho Annual Tax Liability

Maximize traditional 401(k) contributions — the 2026 limit is $23,500 ($31,000 if age 50+). At 5.3% Idaho + 22% federal = 27.3% combined marginal rate, every $1,000 contributed saves $273.
Contribute to an HSA — $4,300 (self-only) or $8,550 (family) in 2026. HSA reduces both federal and Idaho taxable income.
Idaho College Savings Program (IDeal 529) — contributions up to $6,000 (single) or $12,000 (MFJ) per year are deductible from Idaho taxable income. At 5.3%, $6,000 saves up to $318 in Idaho state tax annually.
Contribute to an IRA — traditional IRA contributions (up to $7,000 or $8,000 age 50+) reduce Idaho taxable income if you qualify for the deduction.
Itemize Idaho deductions when beneficial — taxpayers who itemize for federal purposes may itemize for Idaho as well. If mortgage interest, property taxes, and charitable contributions exceed $14,600 (single), itemizing reduces Idaho taxable income below the standard deduction floor.

Idaho's No-Local-Tax Advantage

Unlike states such as Ohio (600+ municipal tax authorities) or Maryland (county piggyback taxes), Idaho levies no local income tax in any city or county. Boise, Nampa, Idaho Falls, and Pocatello residents pay only the flat 5.3% state rate on top of federal tax. For someone earning $90,000, this saves roughly $900–$2,250 per year compared to a worker in a state with a 1%–2.5% local tax. Use the Idaho paycheck calculator to see the per-paycheck impact alongside your federal withholding.

Tax Disclaimer

This calculator provides estimates for informational purposes only. It is not tax advice. Idaho state tax rates, standard deduction amounts, and federal rules change each year. Results reflect 2025 and 2026 tax-year parameters. Consult a qualified tax professional or CPA for guidance on your specific situation.

Sources & References

IRS Publication 17: Your Federal Income Tax — Internal Revenue Service
Social Security Contribution and Benefit Base — Social Security Administration
Idaho Withholding Guide 2026 — Employer Withholding Tables — Idaho State Tax Commission

Idaho Income Tax Calculator