Idaho Paycheck Calculator 2026 — Flat 5.7% State Rate (Federal + FICA + State)

How much do I take home in Idaho? — short answer first

Idaho transitioned from a 4-bracket progressive income tax (1-6.5%) to a flat 5.695% rate under HB 521 (2023), effective tax year 2024+. The standard deduction conforms to federal ($14,600 single / $29,200 joint, indexed). Idaho has no local income tax, and property tax is among the lowest in the US (~0.49% effective). The flat-rate adoption simplified Idaho filing while maintaining a competitive position relative to peers like Utah (4.45% projected) and Montana (5.9% projected). Idaho has no reciprocity agreements — Washington commuters (no income tax) and Oregon commuters (high tax) face full ID rates on Idaho-source wages.

How Idaho taxes payroll in 2026

Idaho levies a flat 5.695% individual income tax under Idaho Code §63-3024A, effective tax year 2024+ per HB 521 (2023). The legislation collapsed Idaho's previous 4-bracket progressive structure (1%, 3%, 4.5%, 6.5%) into a single flat rate. The 5.695% rate is permanent in state code — not subject to revenue triggers like neighbouring Utah or Montana. The flat-rate adoption was the culmination of multi-year tax reform in Idaho; prior to HB 521, the state had progressively flattened its schedule from 7 brackets (2017) to 4 brackets (2022) to a single rate (2024). The 5.695% rate is materially higher than typical flat-tax peers — Utah (4.45% projected 2026), Indiana (2.95% projected 2026), Kentucky (3.5% projected 2026), and Michigan (4.25% permanent). Idaho's competitive position depends on the federal-conforming standard deduction: $14,600 single / $29,200 joint (2024, with annual inflation indexing to ~$15,000 / $30,000+ for 2026). This makes Idaho's effective tax burden on middle-income filers competitive with flat-tax peers despite the higher headline rate. There is no local income tax anywhere in Idaho — Boise, Coeur d'Alene, Idaho Falls, and Twin Falls all fund services through property tax (effective rate ~0.49% statewide — among the lowest in the US) and 6.6% combined sales tax average (6% state + ~0.6% local). Idaho's property tax is significantly lower than neighbouring Oregon (~0.86%) and Washington (~0.93%), which contributes to its competitive overall tax position. Idaho has no reciprocity agreements with any neighbouring state. Washington commuters working in Idaho (no income tax in WA but ID employer withholds at 5.695%) pay the full Idaho rate on Idaho-source wages. Oregon commuters working in Idaho pay both ID tax + claim a credit on the OR return. Cross-border workers should consult a CPA for the OR-ID corridor; the lack of reciprocity creates dual-filing friction.

Idaho state income tax brackets (single filer, 2026)

Standard deduction (single): $14,600 · top marginal rate 5.70%. Married filing jointly + head of household brackets follow the same shape with adjusted thresholds.

Idaho city callouts

• Boise — Property tax ~0.65% effective (slightly above ID average); combined sales tax 6.6%; tech (HP + Micron) + state government anchor; explosive growth post-2020.
• Coeur d'Alene — Property tax ~0.55% effective; combined sales tax 6.6%; popular WA-state-tax-flight destination; Spokane-area commuters drive cross-border friction.

How to use this calculator

1. Enter your annual gross salary. Pre-tax, what your employer pays before any deductions.
2. Pick filing status. Single, married filing jointly, married filing separately, or head of household. Drives both federal and Idaho brackets.
3. Add 401(k) and HSA contributions (optional). Both lower your federal taxable income; HSA also lowers FICA wages.
4. Read the verdict. Annual + monthly + bi-weekly take-home, federal + state + local breakdown, and effective tax rate.

Common mistakes

• Confusing gross with adjusted gross. The calculator wants your gross salary — what your employer pays before any pre-tax deductions or contributions. If you enter your W-2 Box 1 (already net of 401k), the math will under-count your tax.
• Forgetting that 401(k) is still subject to FICA. Traditional 401(k) reduces federal income tax but NOT Social Security + Medicare. Only HSA (through payroll) reduces both.
• Using the wrong filing status for state tax. Idaho uses the same filing status categories as the IRS, but bracket thresholds differ from federal. Pick the status that matches your actual tax filing — not just what gives the best number.
• Ignoring multi-state implications. If you work in Idaho but live elsewhere (or vice versa), you may owe taxes in both states with a credit between them. This calculator assumes you both live and work in Idaho.

Methodology & Sources

Federal income tax + FICA: IRS Pub 15-T 2026 projected brackets + Social Security Administration 2026 wage base ($181,000) + Medicare 1.45% (no cap) + Additional Medicare 0.9% above $200K/$250K thresholds. Idaho state income tax: Idaho State Tax Commission — flat 5.695% individual income tax (post-HB 521) — last verified 2026-05-13. Brackets refresh annually — most state DORs publish updates in Q4 preceding the tax year. Federal 2026 figures are projected from 2025 (Rev. Proc. 2024-40) with ~2.5% inflation adjustment; refresh against IRS October release.

Frequently asked questions

Want to compare Idaho take-home pay against another state? Use the national take-home pay calculator with a flat-rate state input. To see what you'd save by changing your 401(k) contribution, drop the gross salary into the salary-to-hourly calculator. For cost-of-living adjustments when comparing jobs across states, the cost of living calculator adjusts for housing + groceries + tax differences between metros.