If you earn 1099 or self-employment income in Missouri, the IRS and the state both expect you to pay taxes as you go — in four quarterly installments rather than one April bill. This calculator estimates your 2026 quarterly payments across all three pieces: federal self-employment tax, federal income tax, and Missouri state income tax. Missouri's top rate is 4.7% for 2025, and the first $1,313 of income is taxed at 0%. Enter your expected net self-employment income, any W-2 wages, and your filing status to see what to send each quarter, your due dates, and how the safe-harbor rules protect you from an underpayment penalty. Everything is an estimate for planning — always confirm with the Missouri Department of Revenue before you file.
Self-employment income has no tax withheld for you, so both the IRS and Missouri Department of Revenue ask you to prepay in quarterly installments. On the federal side you owe self-employment tax (15.3% Social Security and Medicare on 92.35% of your net profit, up to the Social Security wage base) plus federal income tax on your profit after the standard deduction. On top of that, Missouri applies its own income tax.
Missouri sets its own threshold for when estimated payments become mandatory — check with Missouri Department of Revenue for the current figure. Missouri follows the federal schedule: April 15, June 15, September 15, and January 15. Missouri follows the standard four-installment schedule.
You avoid an IRS underpayment penalty by hitting a "safe harbor": paying at least 90% of this year's total tax, or 100% of last year's (110% if your income is higher). Missouri starts from your federal AGI, subtracts the standard deduction and part of your federal income tax, then applies graduated rates topping out at 4.7% (2025). The Kansas City and St. Louis 1% earnings taxes are not included. You can pay online through the Missouri Department of Revenue portal, and the calculator above breaks your total into the federal and Missouri pieces so you can send each to the right place. You can pay online at the Missouri Department of Revenue (payment portal).
For educational purposes only — not tax advice. Tax rules change and individual situations vary; confirm figures with a tax professional and the Missouri Department of Revenue before filing. State tax data last verified 2026-07-05.
Sources: dor.mo.gov, dor.mo.gov.