Income Tax Calculator | TheSmartCalculator

Annual Income ($)

Deductions ($)

Filing Status

📌 Based on 2024 US federal tax brackets. State taxes not included.

About the Income Tax Calculator

Few financial figures matter more than how much of your paycheck you actually keep. Our Income Tax Calculator estimates your US federal income tax based on the current marginal tax bracket system. Enter your gross income, filing status, and any deductions, and you'll see your estimated tax bill, effective tax rate, marginal tax rate, and take-home pay.

Understanding the difference between your marginal rate (what you pay on the last dollar earned) and your effective rate (what you actually pay on average) is one of the most important concepts in personal finance — and one of the most commonly misunderstood.

How It Works

Enter your annual gross income and filing status (single, married filing jointly, married filing separately, or head of household). Choose the standard deduction or enter your itemized deductions. The calculator applies the current federal tax brackets progressively and computes your total tax liability.

Formula / Key Reference

Taxable Income = Gross Income − Standard (or Itemized) Deduction

Tax = Sum of (income in each bracket × bracket rate)

Effective Tax Rate = Total Tax ÷ Gross Income × 100

Marginal Tax Rate = Rate of the highest bracket reached

After-Tax Income = Gross Income − Total Tax

Real-World Example

Single filer, gross income: $85,000, taking the standard deduction ($14,600 for 2024)

Taxable income: $85,000 − $14,600 = $70,400

2024 Federal Tax Brackets (Single):

10% on $0–$11,600: $1,160.00

12% on $11,600–$47,150: $4,266.00

22% on $47,150–$70,400: $5,115.00

Total federal tax: $10,541

Effective tax rate: $10,541 ÷ $85,000 = 12.4%

Marginal rate: 22%

After-tax income: $74,459

Key insight: although this person is in the 22% bracket, they only pay 22% on the income above $47,150 — not on the entire $85,000. Their effective rate of 12.4% is much lower than their marginal rate.

Common Uses

Estimating quarterly estimated tax payments for self-employed individuals

Comparing the tax impact of different income levels or raises

Evaluating the financial benefit of pre-tax deductions (401k, HSA)

Planning whether to itemize or take the standard deduction

Tax planning at year-end (Roth conversions, capital gain timing)

Frequently Asked Questions

What is the difference between marginal and effective tax rate? ▼

The marginal tax rate is the rate you pay on your last dollar of income — it is the rate of your highest bracket. The effective tax rate is the percentage of your total income paid in taxes. Because the US uses a progressive bracket system, most people's effective rate is much lower than their marginal rate.

Should I take the standard deduction or itemize? ▼

Take whichever is larger. For 2024, the standard deduction is $14,600 (single) and $29,200 (married filing jointly). Itemizing makes sense only if your qualifying deductions — mortgage interest, state and local taxes (SALT, capped at $10,000), charitable donations, and medical expenses — exceed these amounts.

Does this include state income tax? ▼

No — this calculator covers US federal income tax only. State income taxes vary widely, from 0% (Florida, Texas, Nevada) to over 13% (California for high earners). Many states also have their own deductions and credits that differ from federal rules.

What is the FICA tax? ▼

FICA taxes fund Social Security (6.2% on wages up to $168,600 in 2024) and Medicare (1.45% on all wages, plus an additional 0.9% for high earners above $200,000 single or $250,000 married). These are separate from income tax and are withheld in addition to it.

🧾 Income Tax Calculator