The State Tax Estimator models state income tax using a user-supplied taxable income amount, an assumed state tax rate, surtax, and credits. It is useful for quick comparisons across scenarios when the applicable state, year, filing status, and income definition are already known.
State systems vary widely: some use flat rates, others use brackets, and some do not impose a broad individual income tax. This calculator therefore does not claim a current rate for any particular state. Enter a blended or scenario rate that matches the rules you are analyzing.
1. Enter state taxable income
Use the income base defined for the state scenario, which may differ from federal taxable income.
2. Choose a scenario rate
Enter a flat rate or an estimated blended rate appropriate to the state and year.
3. Add any surtax
Include a state-level add-on not captured by the main rate.
4. Enter credits
Use credits applicable to the modeled state return.
5. Evaluate the result
Review gross tax, credits applied, and the effective rate for comparison.
The result is a scenario estimate of net state income tax after applying entered credits up to the amount of modeled tax.
Confirm the state’s taxable-income definition, rate structure, credit refundability, and tax year before relying on the estimate.
Given: $72,000 of state taxable income, a 5% rate, a $250 surtax, and $600 of credits.
Calculation: $72,000 × 5% + $250 = $3,850 before credits. $3,850 − $600 = $3,250.
Result: Estimated net state tax is $3,250.
Interpretation: The modeled net tax equals about 4.51% of state taxable income.
Only if that is appropriate for the calculation you want. For total-tax estimates, a blended rate is usually more representative than the top marginal rate.
States can require additions, subtractions, and different deduction rules, creating a separate state tax base.
Enter a 0% rate unless you are modeling a specific state tax that fits this simple income-based structure.
No. Credits are capped at modeled tax, so the page treats them as nonrefundable.
Not unless you intentionally include it in the rate or surtax. A separate local-tax calculation is clearer when local rules differ.