How is a paycheck calculated in Idaho?

Take-home pay in Idaho is gross W-2 wages minus federal income tax (2026 single-filer brackets, $15,750 standard deduction), state income tax (5.8% flat (2026)), and FICA (Social Security 6.2% capped at $183,600 wage base + Medicare 1.45% on all wages, plus 0.9% additional Medicare above $200K single-filer). The page calculator and reference tables apply this stack at common income tiers.

What state taxes does Idaho apply to wages?

Idaho's state income tax structure is: 5.8% flat (2026) . State standard deduction and personal exemption rules differ from federal — see the methodology page for the exact figures applied to the calculator on this page.

What's the difference between marginal and effective tax rate in Idaho?

Marginal rate = the rate applied to your next dollar of income. Effective rate = total tax paid ÷ total gross income. In states with graduated brackets like California or New York, marginal can run 8-10% while effective at $100K is 4-6%. Idaho's structure: 5.8% flat (2026) — see the income-tier reference table on this page for effective rate at each tier.

How does FICA work on the Idaho paycheck?

FICA = Social Security + Medicare. Social Security is 6.2% of wages up to the 2026 wage base of $183,600 ($10,453 max). Medicare is 1.45% on all wages with no cap. An additional 0.9% Medicare applies to wages above $200,000 for single filers. The FICA stack is identical in all 50 states + DC — Idaho's state-level rules don't change FICA.

Are local / city taxes included in this Idaho paycheck calculator?

The headline take-home figure includes federal + state + FICA. Local taxes (city, county, municipal occupational, school district) are not applied to the headline number but are flagged separately for the eight states where they materially change take-home: NY (NYC, Yonkers), PA (Philly, Pittsburgh), MI (Detroit + 22 cities), OH (RITA / CCA cities), KY (most counties), MD (all counties), IN (all counties), and AL (Birmingham, Macon, Bessemer).

Why doesn't Idaho use brackets like California or New York?

Flat-rate state taxes are politically and administratively simpler — one rate, no brackets to update annually, easier withholding, smaller compliance burden for employers. The trade-off is regressive distribution at low incomes (a flat 4-5% tax on a $30K wage is a heavier burden than the same percentage on $200K). About a dozen U.S. states have moved to or maintained flat-rate structures.

How current is the tax data on this Idaho paycheck calculator?

Federal brackets are 2026 (IRS Rev. Proc. 2023-34, single filer). FICA wage base is the 2026 $183,600 figure. Idaho state brackets are 2026 single-filer figures sourced from the Idaho Department of Revenue or Tax Foundation 2026 individual income tax structure summary. Bracket numbers update annually around January; this page is re-synced each tax year. See the methodology · tax page for the complete source list and limitations.

How Much Is My Paycheck After Taxes in Idaho? 2026 Calculator

TL;DR — Idaho take-home

The Idaho state-tax structure is flat-rate (no brackets), which means a raise from $80K to $200K is taxed at the same state percentage at the margin. Federal + state + FICA on $100K = $74,216.

Below-100 RPP (92.2) means Idaho's $74,216 nominal take-home actually buys what $80,463 would buy in an average-cost state — your dollar stretches further on rent and services.

Reference take-home table — Idaho (2026, single filer)

Gross W-2	Federal	State	FICA	Take-home	Effective rate
$40,000	$2,662	$1,406	$3,060	$32,872	17.8%
$60,000	$5,062	$2,566	$4,590	$47,782	20.4%
$80,000	$8,847	$3,726	$6,120	$61,306	23.4%
$100,000	$13,247	$4,886	$7,650	$74,216	25.8%
$130,000	$20,018	$6,626	$9,945	$93,410	28.1%
$160,000	$27,218	$8,366	$12,240	$112,176	29.9%
$200,000	$36,818	$10,686	$14,283	$138,212	30.9%

Standard deductions ($15,750 federal + state-specific 2026 figure) applied before bracket math. FICA = SS 6.2% to $183,600 + Medicare 1.45% (+0.9% above $200K). Local taxes (city/county) not in headline numbers.

How Idaho taxes work — 2026 structure

Flat-rate state income tax — same rate at every income tier

Idaho uses a flat-rate state income tax: 5.8% flat (2026). The flat-rate model means your effective and marginal state-tax rates are identical at every income tier — a simplification compared with graduated states.

The state's 2026 standard deduction is applied before the flat rate. FICA stack is the same as everywhere else (SS + Medicare). Local-tax overlay applies on top of state in some jurisdictions — see the local section below if applicable.

Real take-home — Idaho cost of living adjusted

Metric	Idaho value
BEA Regional Price Parity (all-items, 2023)	92.2 (US = 100)
RPP — goods	95.9
RPP — rents	86.9
RPP — services	68.1
$100K gross take-home (nominal)	$74,216
Real take-home (purchasing power)	$80,463

Idaho sits below the national cost-of-living baseline (RPP 92.2), so a $74,216 nominal take-home expands to $80,463 in real purchasing power — a meaningful arbitrage at this income tier, particularly visible in rents at 86.9.

Compared with Idaho's neighbors at $100K gross

State	$100K take-home	Effective rate	Page
Idaho (this page)	$74,216	25.8%	—
Washington	$79,103	20.9%	Washington paycheck →
Oregon	$70,894	29.1%	Oregon paycheck →
Montana	$74,310	25.7%	Montana paycheck →
Wyoming	$79,103	20.9%	Wyoming paycheck →

Same single-filer assumptions across all rows. Federal + state + FICA only — local taxes not applied here.

Frequently asked — Idaho paycheck

How is a paycheck calculated in Idaho?: Take-home pay in Idaho is gross W-2 wages minus federal income tax (2026 single-filer brackets, $15,750 standard deduction), state income tax (5.8% flat (2026)), and FICA (Social Security 6.2% capped at $183,600 wage base + Medicare 1.45% on all wages, plus 0.9% additional Medicare above $200K single-filer). The page calculator and reference tables apply this stack at common income tiers.
What state taxes does Idaho apply to wages?: Idaho's state income tax structure is: 5.8% flat (2026). State standard deduction and personal exemption rules differ from federal — see the methodology page for the exact figures applied to the calculator on this page.
What's the difference between marginal and effective tax rate in Idaho?: Marginal rate = the rate applied to your next dollar of income. Effective rate = total tax paid ÷ total gross income. In states with graduated brackets like California or New York, marginal can run 8-10% while effective at $100K is 4-6%. Idaho's structure: 5.8% flat (2026) — see the income-tier reference table on this page for effective rate at each tier.
How does FICA work on the Idaho paycheck?: FICA = Social Security + Medicare. Social Security is 6.2% of wages up to the 2026 wage base of $183,600 ($10,453 max). Medicare is 1.45% on all wages with no cap. An additional 0.9% Medicare applies to wages above $200,000 for single filers. The FICA stack is identical in all 50 states + DC — Idaho's state-level rules don't change FICA.
Are local / city taxes included in this Idaho paycheck calculator?: The headline take-home figure includes federal + state + FICA. Local taxes (city, county, municipal occupational, school district) are not applied to the headline number but are flagged separately for the eight states where they materially change take-home: NY (NYC, Yonkers), PA (Philly, Pittsburgh), MI (Detroit + 22 cities), OH (RITA / CCA cities), KY (most counties), MD (all counties), IN (all counties), and AL (Birmingham, Macon, Bessemer).
Why doesn't Idaho use brackets like California or New York?: Flat-rate state taxes are politically and administratively simpler — one rate, no brackets to update annually, easier withholding, smaller compliance burden for employers. The trade-off is regressive distribution at low incomes (a flat 4-5% tax on a $30K wage is a heavier burden than the same percentage on $200K). About a dozen U.S. states have moved to or maintained flat-rate structures.
How current is the tax data on this Idaho paycheck calculator?: Federal brackets are 2026 (IRS Rev. Proc. 2023-34, single filer). FICA wage base is the 2026 $183,600 figure. Idaho state brackets are 2026 single-filer figures sourced from the Idaho Department of Revenue or Tax Foundation 2026 individual income tax structure summary. Bracket numbers update annually around January; this page is re-synced each tax year. See the methodology · tax page for the complete source list and limitations.

Sources & methodology

Federal brackets — IRS Rev. Proc. 2025-32, 2026 single-filer tables, $15,750 standard deduction.
Idaho state brackets — 2026 Idaho Department of Revenue / Tax Foundation 2026 individual income tax structure summary. State standard deduction applied where relevant.
FICA — Social Security 6.2% on wages up to the 2026 wage base of $183,600; Medicare 1.45% on all wages; +0.9% Additional Medicare on wages above $200K (single filer).
BEA Regional Price Parities — 2023 vintage (all-items, goods, services, rents).
See the methodology · tax for full computation details and limitations.

By Marcus Liang · Founder & Editor · Last synced 2026-05-05.

Cross-state comparison: see how Idaho take-home ranks against the other 50 paycheck calculators on the Real Wage Atlas → — four-way ranking by real wage, after-tax take-home, state-tax savings, and cost-of-living arbitrage.