Iowa Income Tax Calculator (2026 Flat Rate)

The formulas

• Taxable income = income - standard deduction - personal exemptions (when applied), not below zero
• Tax = 3.8% x Iowa taxable income (federal taxable income with Iowa modifications)
• Less $40 personal exemption credit each: one single or separate, two joint or head of household
• Iowa income tax = tax from the rate schedule - credits

How it works

Tax year: 2026.

Iowa taxes income at a flat 3.8%. Enter Iowa taxable income: the state starts from federal taxable income, so the federal standard deduction is already in it. The tool computes state income tax only; credits other than those named are not applied.

Senate File 2442 made Iowa's rate a flat 3.8 percent, and in 2026 all taxable income is taxed at that rate. Iowa starts from federal taxable income, so the federal standard deduction is already applied: enter Iowa taxable income. The personal exemption credit is $40, claimed twice on a joint or head of household return, and the 2026 withholding formula keeps the $40 amount. Dependents add $40 each and age 65 or blindness $20; those are not applied.

Local taxes: Most Iowa school districts add a school district surtax, a percentage of the Iowa tax; it is not included.

Illustrative figures only. Check the result against your firm's methodology before relying on it.

Common questions

Sources

• Iowa DOR, IDR announces 2026 individual income tax and interest rates
• Iowa DOR, IA 1040 expanded instructions: exemption credits
• Iowa DOR, 2026 withholding formula ($40 allowance, 3.8%)

Runs in your browser. The figures you type are not sent to CORAA or stored. Check the result against your firm's methodology before relying on it.