What is Idaho's income tax rate in 2024?

Idaho moved to a flat individual income tax of 5.8% for the 2023 tax year, retained for 2024. There is a built-in exempt amount: taxable income up to $4,489 (single) or $8,978 (married filing jointly) is not taxed, and the 5.8% rate applies only to taxable income above that threshold. This replaced Idaho's former graduated brackets.

What is the Idaho standard deduction?

Idaho conforms to the federal standard deduction. For 2024 that is $14,600 for single and married-filing-separately filers, $29,200 for married filing jointly, and $21,900 for head of household. You subtract the standard deduction (or itemized deductions) from income to reach Idaho taxable income.

Does Idaho tax all of my income?

No. You first subtract the standard or itemized deduction to get taxable income, and then the flat 5.8% rate only applies to the portion of taxable income above the exempt threshold ($4,489 single / $8,978 joint in 2024). Income below the threshold is effectively taxed at 0%, which keeps the effective rate well below 5.8% for most filers.

Is this the same as my federal tax?

No. This calculator estimates only the Idaho state income tax. Your federal income tax, FICA (Social Security and Medicare), and any local taxes are separate. Idaho generally starts from federal taxable income but applies its own deduction conformity, exempt amount, and flat rate.

Are Idaho tax credits included?

This estimate applies the standard deduction and exempt threshold but does not include specific credits such as the grocery tax credit, child tax credit, or the credit for taxes paid to other states. Those reduce your final liability further, so your actual Idaho tax may be lower than the estimate shown.

Idaho Income Tax Calculator 2024 — Flat 5.8% Rate

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How Idaho income tax works

Idaho switched from graduated brackets to a flat 5.8% individual income tax beginning with the 2023 tax year, and that rate carries into 2024. The flat rate does not start from the first dollar: Idaho builds in an exempt amount so that taxable income up to roughly $4,489 (single) or $8,978 (married filing jointly) is untaxed, and 5.8% applies only above that. Idaho also conforms to the federal standard deduction, so the calculation starts by subtracting that deduction from your income.

How it works

The calculator runs three steps:

taxable income = max(0, gross income - standard deduction)
taxed portion  = max(0, taxable income - exempt amount)
idaho tax      = taxed portion x 5.8%

The exempt amount and standard deduction both depend on your filing status. The effective rate shown is the Idaho tax divided by your gross income, which is always lower than 5.8% because of the deduction and the exempt threshold.

Example and notes

A single filer earning $70,000 in 2024:

taxable income = $70,000 - $14,600 = $55,400
taxed portion  = $55,400 - $4,489  = $50,911
idaho tax      = $50,911 x 0.058   = $2,952.84

Note: This estimate uses the 2024 flat 5.8% rate, federal-conformed standard deductions, and Idaho’s exempt thresholds. It does not include itemized deductions or credits (grocery, child, other-state). Your actual Idaho liability from Form 40 may be lower after credits. For filing, use the Idaho State Tax Commission tables.