State Income Tax Estimator Formula

Understand the math behind the state income tax estimator. Each variable explained with a worked example.

Formulas Used

Estimated State Tax

state_tax = taxable_income * state_rate / 100

Monthly State Tax

monthly_state_tax = taxable_income * state_rate / 100 / 12

Income After State Tax

after_state_tax = taxable_income * (1 - state_rate / 100)

Variables

VariableDescriptionDefault
taxable_incomeTaxable Income(USD)75000
state_rateState Tax Rate(%)5

How It Works

State Income Tax

State income tax rates vary widely. Some states have no income tax while others charge over 13%.

No Income Tax States

Alaska, Florida, Nevada, New Hampshire (dividends only), South Dakota, Tennessee (dividends only), Texas, Washington, Wyoming

Highest Tax States

California (up to 13.3%), Hawaii (up to 11%), New York (up to 10.9%)

Worked Example

$75,000 income in a state with 5% flat rate.

taxable_income = 75000state_rate = 5
  1. 01State tax = $75,000 x 5% = $3,750
  2. 02Monthly = $3,750 / 12 = $313

Frequently Asked Questions

Which states have no income tax?

Alaska, Florida, Nevada, South Dakota, Texas, Washington, and Wyoming have no state income tax. New Hampshire and Tennessee tax only investment income.

Should I move to a no-tax state?

Consider total tax burden including property tax, sales tax, and cost of living. No-income-tax states often have higher property or sales taxes.

Is this an exact calculation?

This is an approximation using a flat rate. Most states have progressive brackets. Use your state tax authority website for exact calculations.

Ready to run the numbers?

Open State Income Tax Estimator