Idaho Income Tax Calculator
Figure basis: Official Idaho State Tax CommissionIdaho income tax is calculated on your taxable income after deductions and exemptions. This calculator estimates your Idaho state income tax liability for the current tax year. Enter your annual gross income, choose your filing status (single, married filing jointly, married filing separately, or head of household), and add any pre-tax deductions to see your estimated state tax, effective tax rate, and marginal bracket. Results update in real time as you adjust your inputs. The calculator covers Idaho state income tax only; federal income tax, FICA payroll taxes, and any local income taxes your city or county imposes are separate. All rates and brackets are sourced directly from Idaho State Tax Commission and are verified for the current tax year. Use this tool alongside the federal income tax calculator to see your combined total tax liability. Effective rate and marginal rate are both shown so you can evaluate the impact of additional income, filing status changes, or increased pre-tax contributions to a 401(k) or similar plan.
Idaho applies a flat income tax rate of 5.3% to all taxable income. On a $60,000 salary (single filer) the state income tax is $2,345.25, an effective rate of 3.91%.
How Idaho income tax works
Idaho levies a flat individual income tax rate of 5.3% of Idaho taxable income, effective January 1, 2025, reduced from 5.695% by House Bill 40 (2025 session), codified at Idaho Code 63-3024. Idaho technically applies a 0% bracket to the first portion of taxable income (up to $4,811 for single and $9,622 for married filing jointly in 2025), with the 5.3% rate applying above that threshold; the flat rate applies to all filing statuses. Your result updates the page link, so you can copy a permalink to any calculation.
taxable income = gross income - standard deduction
state income tax = taxable income x flat rate / 100
effective rate = state income tax / gross income x 100
Idaho's flat 5.3% and the zero-rate slice most people forget
Idaho switched to a flat individual income tax in 2023, and the rate has fallen twice since. House Bill 40 (2025 session) cut it from 5.695% to 5.3% effective January 1, 2025, codified at Idaho Code 63-3024. The 5.3% applies to every filing status, so a single filer and a married couple face the same marginal rate on each taxable dollar.
The detail that trips people up is that Idaho's flat tax is not flat from the very first dollar. The state applies a 0% rate to an initial slice of taxable income, roughly the first $4,811 for single filers and $9,622 for married filing jointly in 2025, with the 5.3% rate taking over above that. That zero-rate band means the effective rate on a modest income sits meaningfully below 5.3%, and a quick 'income times 5.3%' estimate overstates the bill.
Idaho also conforms to the federal standard deduction, so for 2025 filers subtract $15,750 (single) or $31,500 (married filing jointly) before the rate applies, the larger amounts set by the One Big Beautiful Bill Act. Because the state adopts the federal figure each year, Idaho taxpayers do not track a separate state deduction schedule. The combination of a low flat rate, a generous conforming deduction, and the 0% starting band keeps Idaho's income tax competitive within the Mountain West, and well below the top rates in nearby Oregon.
Idaho income tax: frequently asked questions
How much is the Idaho income tax on a $60,000 salary?
A single filer earning $60,000 a year in Idaho has a taxable income of $44,250.00 after the standard deduction. The computed state income tax is $2,345.25, an effective rate of 3.91%. Enter your own income above for an exact figure.
What is the Idaho state income tax rate?
Idaho applies a flat income tax rate of 5.3% to all taxable income, regardless of income level or filing status.
What filing statuses does Idaho income tax apply to?
Idaho income tax applies to single filers, married couples filing jointly, head of household filers and married couples filing separately. Bracket thresholds and standard deductions may differ by filing status.
What is Idaho's state income tax rate for 2025?
Idaho's flat income tax rate is 5.3% for tax year 2025. The rate was reduced from 5.695% to 5.3% by Idaho House Bill 40 (2025 session), effective January 1, 2025, and applies to all Idaho taxable income for all filing statuses, per Idaho Code 63-3024.
What standard deduction can Idaho residents use?
Idaho conforms to the federal standard deduction. For 2025, the amounts are $15,750 for single filers and married filing separately, $31,500 for married filing jointly, and $23,625 for head of household. These figures are adjusted annually for inflation by the IRS, and Idaho adopts the updated federal amounts each year.
When did Idaho change to a flat income tax?
Idaho adopted a flat individual income tax through HB 1 (2022 special session), effective for tax year 2023. The rate was later reduced to 5.695% and then to 5.3% effective January 1, 2025 under House Bill 40 (2025). The flat rate replaced a graduated structure and applies to all filing statuses.
Does Idaho conform to federal tax rules?
Yes. Idaho conforms to many federal income tax rules, including the federal standard deduction, federal adjusted gross income as the starting point for Idaho taxable income, and certain federal deductions and credits. Idaho does make some modifications to federal AGI on the state return. Review the Idaho State Tax Commission guidance at tax.idaho.gov for the current list of additions and subtractions.
Official sources
- Idaho income tax rates (tax year 2025): Idaho State Tax Commission, as at Jul 16, 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 11 June 2026. See our methodology. General information, not financial or tax advice.