Iowa follows both federal deductions, and unlike most states that do, it never had to pass a law: Iowa starts from your federal taxable income, which the deductions have already reduced, and its tax code tracks federal law as it changes. A flat 3.8% applies, less a credit of $40 — or $80 filing jointly or as head of household. Iowa has no standard deduction of its own because the federal one is already counted.
What it means on a real paycheck
Take a single filer earning $50,000 a year, $8,000 of it in tips. Against the same person with no tips to declare, the federal deduction is worth $960.
In Iowa it is worth $304 more, because the state follows the federal deduction. Together that is $1,264.
How Iowa works out the tax
Iowa charges a flat 3.8%. It begins from your federal taxable income.
Worth knowing about Iowa
It starts from your federal taxable income
Most states begin at your adjusted gross income and apply their own deduction. This one begins after the federal standard deduction has already come off, which is why the two federal deductions can reach it without the state passing any law of its own.
The exemption is a credit, not a deduction
$40 comes off the tax itself rather than off your income, at every income, which is worth more to a low earner than a deduction of the same size.
Where these figures come from
Iowa’s rates and reliefs here were taken from Iowa’s own publication and last checked on 2026-08-02. A state appears in this calculator only once its figures have been read off that state’s own paperwork and covered by tests — never estimated, and never copied from another site.