Idaho charges 5.3% flat state income tax. Use the marriage tax calculator pre-loaded with Idaho rates.
Open Marriage Tax Calculator →Idaho's flat 5.3% state income tax interacts with federal brackets to create marriage bonuses or penalties that differ from the federal-only effect. Since Idaho uses a flat rate, the state tax does not create its own marriage penalty, but it does amplify the federal effect by adding to the total tax burden. This calculator shows the combined federal and Idaho state marriage tax impact.
Idaho levies a flat 5.3% state income tax on all taxable income regardless of how much you earn. This makes tax planning straightforward: for every additional dollar you earn, 5.3 cents goes to Idaho. Idaho does not impose local income taxes, so the 5.3% flat rate is the only state-level income tax you owe.
The table below shows what you actually keep at five salary levels in Idaho, accounting for federal tax, FICA, and Idaho's flat 5.3% state tax.
See how Idaho compares to other West states. Each link takes you to the marriage tax calculator landing page for that state.
For a comprehensive breakdown of Idaho’s tax structure, salary comparisons, cost-of-living analysis, and more, visit the full Idaho take-home pay page.