Iowa's flat 3.8% income tax
Iowa taxes income at a flat 3.8%, whatever the amount and filing status. The Iowa standard deduction is $16,100 for single filers, $32,200 for married couples filing jointly and $24,150 for heads of household — the same amounts as the federal deduction.
This is Iowa's 2025 schedule, the latest the calculator has. It was checked on 2026-09-30 against Iowa DOR press release 2025-10-21 (3.8% for 2026); Iowa DOR Impact of One, Big, Beautiful Bill Act (starting point is federal taxable income, rolling conformity).
Some Iowa school districts levy a surtax on state income tax that is not included here.
Iowa and federal income tax by income
At the calculator's default $85,000, Iowa takes $2,618 of a $12,488 total income tax bill, or 21%. Filing status matters too: a married couple filing jointly on $170,000 owes Iowa $5,236 — exactly what two single filers earning $85,000 each would pay.
| Gross income | Iowa tax | Iowa rate | Federal tax | Combined effective rate |
|---|---|---|---|---|
| $30,000 | $528 | 1.76% | $1,420 | 6.49% |
| $50,000 | $1,288 | 2.58% | $3,820 | 10.22% |
| $65,000 | $1,858 | 2.86% | $5,620 | 11.50% |
| $85,000 (default) | $2,618 | 3.08% | $9,870 | 14.69% |
| $100,000 | $3,188 | 3.19% | $13,170 | 16.36% |
| $125,000 | $4,138 | 3.31% | $18,734 | 18.30% |
| $200,000 | $6,988 | 3.49% | $36,734 | 21.86% |
| $300,000 | $10,788 | 3.60% | $68,134 | 26.31% |
| $400,000 | $14,588 | 3.65% | $103,134 | 29.43% |
Marginal tax rate in Iowa
The next dollar a single filer earns above $85,000 is taxed at 25.8%: 22% federal and 3.8% by Iowa. Because Iowa's rate is flat, its share of a raise stays 3.8% at any income above the standard deduction.