GA
Georgia
5.19% top marginal rate
ID
State · 2026 tax year · Flat Tax
Idaho 2026 Income Tax
According to the Idaho Department of Revenue August 2026 schedule, Idaho applies a flat 5.30% to all taxable income. Walk the math and compute your full federal + state + FICA take-home.
$5,300 state tax on $100K
A single filer with $100,000 of taxable income in Idaho owes $5,300 in state income tax (5.30% effective; structure: Flat Tax). Rank #40 of 51 by state-tax burden (1 = lowest).
- Burden rank #40 of 51 at $100K single
- Top marginal rate 5.30%
- 2026 tax year · IRS + state DOR schedules
Idaho at $100K, in one line
A single filer earning $100,000 of taxable income owes $5,300 in Idaho state income tax, a 5.30% effective rate, well below the 5.30% headline top rate. That ranks Idaho#40 of 51 jurisdictions by state-tax burden (1 = lowest), under a single flat rate.
Idaho Department of Revenue 2026 schedule · Tax Foundation How we calculate →
$5,300
state tax at $100K
5.30%
effective state rate
#40
of 51 1 = lowest
5.30%
top marginal rate
Gross income
$116,100 100.0%
Federal income tax
$16,712 14.4%
FICA / SECA
$8,882 7.7%
State income tax
$5,300 4.6%
Take-home pay
$85,206 73.4%
State income-tax bracket ticket
Idaho DOR bracket ticket ID · 2026 · flat
Idaho · $5,300 @ $100K · #40/51
Idaho line from the 2026 Department of Revenue schedule vs IRS Rev. Proc. 2025-32, reference math, not a filing. Read with Idaho → · Model your own →
Idaho in the $100K burden neighbourhood
Idaho effective state rate at $100K (single filer) 5.3%
Federal effective @ $100K
The percentage is Idaho's state income tax at $100K of taxable income, not a fill-ratio against federal. The marker is the ~16.9% federal effective rate at the same income. The heaviest state income-tax line at $100K is about 8.4% (Oregon), so state tax stacks well under federal in every state.
How Idaho compares to nearby states on the burden scale
States immediately above and below Idaho on the $100K single-filer burden scale, sorted by burden ascending.
The comparison ranks 5 states clustered around Idaho on burden, not by geographic proximity. The Selected tag marks Idaho; cards on either side show the next-cheaper and next-more-expensive jurisdictions, useful for understanding whether your state's rate is broadly competitive in its tier or an outlier. Each peer card links to its own bracket schedule for a deeper comparison.
MT
Montana
5.65% top marginal rate
ID
Idaho
5.30% top marginal rate
SC
South Carolina
6.00% top marginal rate
NY
New York
10.90% top marginal rate
About Idaho 2026 Income Tax
Idaho applies a flat 5.30% income tax to all taxable income, one of fourteen US flat-rate jurisdictions. The flat structure produces predictable per-dollar tax cost regardless of income level, simplifying filing relative to the twenty-eight progressive-bracket states. At $100,000 single-filer 2026 taxable income Idaho state tax equals approximately $5300. Combined with federal income tax ($16,914 single, 2026) and FICA ($7,650 on $100K wages) the total tax burden equals roughly $29864 - effective combined rate 29.86%.
Key Idaho Tax Notes (2026)
Flat 5.3% rate (retroactively reduced from 5.695% via H.B. 40, March 2025).
Source: Idaho Department of Revenue, 2026 personal income tax publications. Source: Tax Foundation State Individual Income Tax Rates and Brackets 2026. Source: IRS Revenue Procedure 2025-32, 2026 federal inflation adjustments.
2026 Federal Brackets That Stack on Idaho (Single Filer)
State income tax applies after federal brackets on the same taxable income base. Federal rows from IRS Rev. Proc. 2025-32; compare the full federal hub at /federal/.
| Taxable income range | Federal marginal rate |
|---|---|
| $0 – $12,400 | 10.00% |
| $12,400 – $50,400 | 12.00% |
| $50,400 – $105,700 | 22.00% |
| $105,700 – $201,775 | 24.00% |
| $201,775 – $256,225 | 32.00% |
| $256,225 – $640,600 | 35.00% |
| $640,600 and above | 37.00% |
2026 Federal Brackets (Married Filing Jointly)
| Taxable income range | Federal marginal rate |
|---|---|
| $0 – $24,800 | 10.00% |
| $24,800 – $100,800 | 12.00% |
| $100,800 – $211,400 | 22.00% |
| $211,400 – $403,550 | 24.00% |
| $403,550 – $512,450 | 32.00% |
| $512,450 – $768,700 | 35.00% |
| $768,700 and above | 37.00% |
Source: IRS Revenue Procedure 2025-32, 2026 inflation-adjusted brackets.
Combined Idaho + Federal + FICA at Common Incomes (Single)
Taxable-income tiers walk the published Idaho schedule plus IRS federal brackets and 2026 FICA on gross wages before the $16,100 standard deduction. Reference math only.
| Taxable income | Idaho tax | Federal tax | FICA | Total tax | Est. take-home |
|---|---|---|---|---|---|
| $50,000 | $2,650 | $5,752 | $5,057 | $13,459 | $52,641 |
| $100,000 | $5,300 | $16,712 | $8,882 | $30,894 | $85,206 |
| $200,000 | $10,600 | $40,598 | $14,717 | $65,915 | $150,185 |
Source: Idaho Department of Revenue 2026 schedule · IRS Rev. Proc. 2025-32 · 2026 FICA rates from IRS/SSA publications.
Idaho ranks #40 of 51 US jurisdictions by state tax burden at $100K single-filer income (1 = lowest burden).
Quick Idaho State Tax Estimate
Enter taxable income and filing status to see Idaho state tax owed for 2026. The estimate walks the matching Department of Revenue bracket schedule (single and married-jointly are separate keys when the state publishes different widths). For full federal + state + FICA, use the main calculator.
Compare with Nearby-Burden States
Read with this jurisdiction
Drills shaped by Idaho's flat tax architecture, not a generic tool list.
- Run Idaho in the 2026 calculator
Stack federal + FICA + this state on your own income
- Effective vs marginal rate
Flat 5.30% makes effective ≈ marginal on state income
- Georgia (flat 5.19%)
Nearest same-structure peer at $100K (Δ $110)
- Illinois (flat 4.95%)
Nearest same-structure peer at $100K (Δ $350)
- Full state tax rankings hub
See where Idaho lands across $50K / $100K / $200K tiers
Every figure on PlainTaxCalc is rendered directly from IRS Revenue Procedure and state Department of Revenue data, no number is typed in by an editor. This state's figures are rendered directly from IRS Revenue Procedure and state Department of Revenue data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data issue on this page. Data current as of August 2026.
A published rate is a schedule line, not a filing recommendation. The calculator's take-home figure applies the standard deduction only, it excludes credits, AMT, and itemized deductions. These pages explain the issued tables; they are not tax advice.