Side Income Tax Calculator for Missouri

Side income in Missouri is subject to federal income tax at your marginal rate, self-employment tax if applicable, and a flat 4% Missouri state income tax. Because side income typically stacks on top of your W-2 salary, it is often taxed at your highest marginal rates. Local income taxes in some Missouri jurisdictions add further cost. 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 Missouri.

Missouri levies a flat 4% state income tax on all taxable income regardless of how much you earn. This makes tax planning straightforward: for every additional dollar you earn, 4 cents goes to Missouri. However, certain localities in Missouri impose their own income taxes, which effectively raise the combined state and local rate above 4%. Be sure to check whether your city or county adds a local income tax.

The table below shows what you actually keep at five salary levels in Missouri, accounting for federal tax, FICA, and Missouri's flat 4% state tax plus estimated local taxes.

See how Missouri 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 Missouri’s tax structure, salary comparisons, cost-of-living analysis, and more, visit the full Missouri take-home pay page.