Missouri Income Tax Calculator - MO State Tax Estimate

The missouri income tax calculator estimates your annual Missouri individual income tax from your federal adjusted gross income. Missouri applies one flat state rate to your Missouri taxable income, so the calculator takes your IRS Form 1040 AGI, subtracts the standard deduction for your filing status plus $2,500 for each dependent, and multiplies the remainder by the flat rate for the year you choose.

• • Plan a year-end tax payment: See what you owe before sending a fourth-quarter estimate to the Missouri Department of Revenue.
• • Compare filing years: Compare 2024, 2025, and 2026 because the flat rate steps down each year under Missouri's rate-reduction law.
• • Check a refund or balance due: Turn your expected liability into a refund or amount-due figure once you subtract Missouri withholding.
• • Model a raise or bonus: Estimate how a higher AGI changes state tax now that the rate is flat rather than bracketed.

Because Missouri no longer uses graduated brackets for individuals, the math is simpler than in many states, but the standard deduction and dependent exemptions still matter. The calculator focuses on the state piece only; it does not compute your federal tax.

Use the result as a planning estimate. Your actual Missouri liability also depends on itemized deductions, credits, and withholdings reported on your return. For per-paycheck withholding rather than an annual figure, the Missouri paycheck calculator works from the same flat rate across each pay period.

The estimate is most useful for Missouri residents and part-year residents who earn taxable income reported on a federal return. If you are a nonresident with only Missouri-source income, the same flat rate applies but the starting point differs, so confirm your residency status before relying on the figure for a payment.

If you are married and both spouses earn income, enter the combined federal AGI with the married filing jointly status, because Missouri's standard deduction for that status is $5,000 and each dependent adds another $2,500 of exemption.

If you want a per-paycheck view instead of an annual figure, the Missouri paycheck calculator applies the same flat rate across each period.

The calculator follows the same steps the Missouri return uses: start with federal AGI, subtract the standard deduction for your filing status, subtract $2,500 per dependent, then apply the flat rate.

• federalAGI: Your federal adjusted gross income from IRS Form 1040.
• standardDeduction: The Missouri amount for your filing status: $2,500 single, $3,500 head of household, or $5,000 married filing jointly.
• dependents: Each qualifying dependent adds a $2,500 personal exemption to your deduction.
• flatRate(year): The single Missouri rate: 4.8% in 2024, 4.7% in 2025, and 4.5% in 2026.

Missouri taxable income is never negative; if your deductions exceed AGI, the calculator reports zero taxable income and zero tax. The flat rate is applied to whole-dollar taxable income.

The same flat-rate logic appears in the federal income tax calculator for the federal side, but Missouri uses a single rate while the federal system still uses brackets.

According to Missouri Department of Revenue, Missouri applies a single flat individual income tax rate, with scheduled reductions to 4.8% for 2024, 4.7% for 2025, and 4.5% for 2026.

For the federal side of the same return, the federal income tax calculator shows how brackets apply above the line where Missouri starts.

Four ideas explain why the number moves the way it does.

These four ideas are enough to predict the result. If you want to convert the annual figure into a pay-period view, the gross-to-net calculator shows take-home impact after tax.

If you want to see the take-home impact of this annual tax, the gross-to-net calculator turns the same numbers into a per-period view.

Follow these steps to get a clean estimate.

1. 1 Enter federal AGI: Pull the AGI figure from your IRS Form 1040, line 11, and enter it as Federal AGI.
2. 2 Pick filing status: Choose single, married filing jointly, married filing separately, or head of household; this sets the standard deduction.
3. 3 Add dependents: Enter the number of qualifying dependents; each one adds $2,500 to your deduction.
4. 4 Select the tax year: Choose 2024, 2025, or 2026 so the calculator uses the correct flat rate for that year.
5. 5 Read the outputs: Note Missouri taxable income, state tax, and the effective state rate as a percent of AGI.
6. 6 Compare against withholding: Subtract Missouri withholding already paid to see a refund or balance due.

A married couple with $100,000 AGI in 2025 and two dependents enters those values, sees $90,000 taxable income (5,000 standard deduction plus 5,000 of exemptions), and a $4,230 state tax at the 4.7% rate.

If you only have gross income and need the adjusted figure first, the AGI calculator builds the federal AGI the Missouri estimate expects.

Running the estimate before you file helps you make specific decisions.

• • Avoid underpayment penalties: A year-end estimate shows whether your withholding covers the flat-rate liability so you can send a payment if needed.
• • Time a Roth conversion: Because the rate is flat, you can see the extra Missouri tax from added income without bracket surprises.
• • Plan a bonus or raise: Model how a one-time amount changes state tax when every dollar is taxed at the same rate.
• • Capture dependent exemptions: The tool shows the $2,500-per-dependent exemption so you can confirm you are claiming every qualifying dependent.
• • Track the rate phase-down: Comparing years reveals the savings from Missouri's step-down from 4.8% toward 4.5%.
• • Coordinate with payroll: Share the annual figure with your employer's withholding so each paycheck comes out close.

The estimate is informational. Your filed return may differ after credits, other subtractions, and final withholdings are applied.

When the salary behind the AGI is prorated across the year, the annual income calculator annualizes it so the estimate lines up.

Several inputs change the result; a few limits apply.

• • The calculator estimates individual income tax only; it excludes Missouri credits, itemized deductions, local earnings taxes, and federal tax.
• • Standard deduction and rate figures shown are the published amounts and may be updated by the Department of Revenue; confirm the current year's instructions before filing.

Missouri also does not tax Social Security benefits, and the flat rate means planning is more predictable than in bracketed states. When the salary behind the AGI is easier to read as an annual figure, the annual income calculator annualizes the amount for you.

Because the rate is flat, a dollar of extra income above the deduction and exemptions adds the same percentage of state tax whether it comes from a raise, a side job, or a retirement distribution. The main moving parts are therefore the standard deduction for your status, your dependent exemptions, and the year's flat rate, not a bracket boundary.

As published by Internal Revenue Service, Missouri filers begin with federal adjusted gross income reported on IRS Form 1040 before applying the state standard deduction and exemptions.

To compare how a flat-rate neighbor handles the same AGI, the Mississippi income tax calculator runs the parallel estimate with Mississippi's rate.