Side Income Tax Calculator for Iowa

Side income in Iowa is subject to federal income tax at your marginal rate, self-employment tax if applicable, and a flat 3.8% Iowa state income tax. Because side income typically stacks on top of your W-2 salary, it is often taxed at your highest marginal rates. The combined marginal rate on side income can easily exceed 40% for mid-to-high earners. This calculator breaks down exactly what you keep from each dollar of side income in Iowa.

Iowa levies a flat 3.8% state income tax on all taxable income regardless of how much you earn. This makes tax planning straightforward: for every additional dollar you earn, 3.8 cents goes to Iowa. Iowa does not impose local income taxes, so the 3.8% flat rate is the only state-level income tax you owe.

The table below shows what you actually keep at five salary levels in Iowa, accounting for federal tax, FICA, and Iowa's flat 3.8% state tax.

See how Iowa compares to other Midwest states. Each link takes you to the side income tax calculator landing page for that state.

For a comprehensive breakdown of Iowa’s tax structure, salary comparisons, cost-of-living analysis, and more, visit the full Iowa take-home pay page.