Bonus Tax Calculator — Idaho (2026)
Bonuses in Idaho are taxed as supplemental wages: the employer usually withholds a flat 22% federal, plus 7.65% FICA and Idaho state withholding. Withholding is not the final tax; the true cost is settled on your return. Enter your bonus to see both. Idaho uses a flat personal income tax of 5.30% applied to taxable income after a state standard deduction of $16,100.
Idaho Bonus Tax Calculator
The gross bonus before withholding.
Percentage method vs aggregate method
Under the percentage method the bonus is separated from regular pay and hit with the flat 22% federal rate (37% above $1 million of supplemental wages in a year). Under the aggregate method the employer combines the bonus with your normal check and withholds at your marginal rate — which can temporarily withhold far more than 22%.
Either way the bonus is ordinary income. If your marginal federal bracket is 24% or higher, the 22% flat withholding leaves you short at filing time; if you are in the 12% bracket, you are over-withheld and get it back as a refund.
The Idaho layer on bonuses
Idaho taxes bonus income at the same flat rate as salary — up to 5.30%. A $10,000 bonus therefore carries roughly $530 of Idaho tax at the top rate, on top of federal and FICA.
Idaho has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Reducing the tax on a Boise bonus
Deferring part of the bonus into a 401(k) or HSA cuts federal and Idaho income tax immediately, though FICA still applies. Some employers allow a separate bonus deferral election — ask payroll before the payment date, not after.
Timing matters too: pushing a bonus into January shifts the tax year, useful if this year included unusually high income from tech work or an equity event.
Local and payroll taxes Idaho adds on top
Idaho adds no state-mandated employee payroll deduction beyond FICA, so nothing extra is taken from your gross pay at the state level.
Idaho has no separate city or county income tax, so the state figure above is the full sub-federal income tax you pay.
Bonuses are wages, so every local layer that applies to your regular Idaho paycheck applies to the bonus too — which is why a supplemental payment often nets a smaller share than your salary does.
Working across a state line from Idaho
Idaho has no income-tax reciprocity agreements, so if you live here and work across a state line you generally file a nonresident return in the work state and claim a credit at home to avoid double taxation.
Remote and hybrid work complicates this further: most states tax income where the work is physically performed, so a Boise resident spending part of the year at a client site in Washington may owe a nonresident return there. Keep a day-count log if you split time between states.
The rest of your Idaho tax bill
Idaho charges a 6% state sales tax, homeowners pay an average effective property tax of 0.63% of market value, and the minimum wage in force during 2026 is $7.25 an hour.
Few local add-ons, so 6% is close to the effective statewide rate.
Income tax is only one part of a state's take. Idaho recovers revenue through sales and property tax as well, which is why headline income tax rates alone are a poor guide to how far a salary really goes. Idaho exempts Social Security and offers a limited deduction for certain public pensions at 65+.
Idaho vs Washington on the same salary
On a $75,000 salary, a single filer keeps about $58,471 a year in Idaho against roughly $61,593 in Washington — a difference of $3,122, or $260 a month.
Effective combined rates are 22.0% in Idaho and 17.9% in Washington. Set that gap against living costs: index 99 here versus 116 there, with property tax at 0.63% and 0.94% respectively.
Idaho income tax brackets 2026 (single filer)
| Taxable income | Rate |
|---|---|
| $0 and up | 5.30% |