What is Iowa's income tax rate for 2025?

Iowa uses a single flat income tax rate of 3.80% for 2025, completing a multi-year phase-down from a graduated system. Every taxpayer pays the same 3.80% marginal rate on taxable income above the standard deduction, regardless of income level.

What were Iowa's 2024 tax brackets?

In 2024 Iowa used transitional graduated brackets for single filers: 4.40% up to $6,210, 4.82% to $31,050, 5.70% to $75,420, and 6.00% above that. Married-filing-jointly thresholds were double the single amounts. These were the last graduated brackets before the 2025 flat rate took effect.

What standard deduction does Iowa use?

Iowa now conforms its standard deduction to the federal standard deduction, so the deduction matches the federal figure for your filing status — about $15,000 for single filers and $30,000 for joint filers. This calculator subtracts that conformed deduction before applying the Iowa rate.

Is there a local income tax in Iowa?

Iowa does not levy a separate municipal or county income tax on wages. However, some Iowa school districts impose a surtax calculated as a percentage of your state income tax, which is filed with your return. This calculator covers state income tax only and does not add school-district surtaxes.

What is the difference between effective and marginal rate?

Your marginal rate is the rate applied to your last dollar of taxable income — 3.80% under the 2025 flat tax. Your effective rate is total tax divided by total income, which is lower because the standard deduction shields part of your income. This tool reports both so you can see your true average burden.

Iowa Income Tax Calculator — Flat 3.8% & 2024 Brackets

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This calculator computes your Iowa state income tax under either the 2025 flat 3.80% rate or the 2024 transitional graduated brackets. It applies Iowa’s conformed standard deduction and reports your tax along with effective and marginal rates, so you can compare years or check a return.

How it works

Iowa taxes income above the standard deduction:

Taxable income = Income − standard deduction

Then the rate depends on the year:

2025 (flat): tax = taxable × 3.80%.
2024 (graduated): the brackets 4.40% / 4.82% / 5.70% / 6.00% apply to successive slices of taxable income, so only the income within each band is taxed at that band’s rate.

Effective rate = tax ÷ income (lower than the marginal rate because the deduction shields part of your income).

Iowa income tax details

Iowa flattened its income tax to 3.80% in 2025, the final step of a phase-down that once topped out near 9%. Because Iowa conforms to the federal standard deduction, a large slice of income is excluded before the rate applies. There is no local income tax on wages, though some school districts add an annual surtax filed on your return.

Worked example

A single filer with $60,000 of income in 2025:

Taxable income = $60,000 − $15,000 = $45,000
Tax = $45,000 × 3.80% = $1,710
Effective rate on income = $1,710 ÷ $60,000 ≈ 2.85%

Note: This covers state income tax only — not federal tax, FICA, credits, or school-district surtaxes. Verify figures with the Iowa Department of Revenue before filing.