Marginal Tax Rate Calculator Formula
Understand the math behind the marginal tax rate calculator. Each variable explained with a worked example.
Formulas Used
Marginal Rate
marginal_bracket = marginal_rateTax on Extra Income
tax_on_raise = raise_amount * marginal_rate / 100After-Tax Extra Income
after_tax_raise = raise_amount * (1 - marginal_rate / 100)Variables
| Variable | Description | Default |
|---|---|---|
taxable_income | Taxable Income(USD) | 75000 |
raise_amount | Raise or Extra Income(USD) | 5000 |
marginal_rate | Derived value= taxable_income <= 11600 ? 10 : (taxable_income <= 47150 ? 12 : (taxable_income <= 100525 ? 22 : 24)) | calculated |
How It Works
Marginal Tax Rate
Your marginal rate is the tax rate on your next dollar of income. A $5,000 raise at 22% marginal rate means $1,100 in additional tax.
After-Tax Raise = Raise x (1 - Marginal Rate)
Important: Getting a raise never results in less take-home pay. Only the additional income is taxed at the higher rate.
Worked Example
$75,000 income with a $5,000 raise.
- 01Marginal rate at $75,000 = 22%
- 02Tax on $5,000 raise = $5,000 x 22% = $1,100
- 03After-tax raise = $5,000 - $1,100 = $3,900
Frequently Asked Questions
Can a raise push me into a higher bracket and cost me money?
No. Only the income above the bracket threshold is taxed at the higher rate. A raise always results in more take-home pay.
What is my total marginal rate?
Add federal marginal rate + state rate + FICA (7.65% if employed). For someone in the 22% federal bracket in a 5% state: about 34.65% total marginal rate.
Why does marginal rate matter?
It determines the tax impact of deductions, contributions, and additional income. A $1,000 401(k) contribution saves $220 in a 22% bracket vs $120 in a 12% bracket.
Learn More
Guide
Tax Bracket Guide
Understand how U.S. federal tax brackets work, the difference between marginal and effective tax rates, and strategies to reduce your tax burden legally.
Ready to run the numbers?
Open Marginal Tax Rate Calculator