Federal Income Tax Calculator (Married Filing Jointly)

Use this professional-grade calculator to estimate US federal income tax for a Married Filing Jointly (MFJ) household. It applies the official IRS tax brackets and standard or itemized deductions to provide a clear breakdown by bracket, effective and marginal rates.

Calculator

Deduction selection
The standard deduction is applied automatically when selected and varies by year.

Results

Enter your details to see your federal income tax estimate.

Adjusted Gross Income (AGI) $0
Deduction used $0
Taxable income $0
Estimated federal tax $0
Effective tax rate 0%
Marginal tax rate 0%
Bracket breakdown

    This tool estimates federal income tax before credits. It does not include FICA payroll taxes or the Alternative Minimum Tax (AMT).

    Data Source and Methodology

    Authoritative data source: IRS Revenue Procedure 2023-34 (November 9, 2023) — inflation adjustments for tax year 2024, including marginal rate tables and the standard deduction. Direct link: IRS: Tax inflation adjustments for 2024.

    For tax year 2023, thresholds are based on IRS Revenue Procedure 2022-38. All brackets shown are for Married Filing Jointly.

    Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.

    The Formula Explained

    $$\mathrm{AGI} = \max\{0,\, \text{Gross Income} - \text{Adjustments}\}$$ $$\mathrm{Taxable\ Income} = \max\{0,\, \mathrm{AGI} - \text{Deduction}\}$$ $$\mathrm{Tax} = \sum_{i=1}^{n} \left( \min\{\max(0,\, T - L_i),\, U_i - L_i\} \cdot r_i \right) \quad \text{where } T=\mathrm{Taxable\ Income}$$ $$\mathrm{Effective\ Rate} = \frac{\mathrm{Tax}}{\text{Gross Income}} \qquad \mathrm{Marginal\ Rate} = r_k \text{ where next \$1 falls}$$ where each bracket i has lower bound L_i, upper bound U_i (last bracket has U_n=\infty), and rate r_i.

    Glossary of Variables

    Gross Income: Total MFJ ordinary income before deductions.
    Adjustments: Above-the-line deductions (e.g., deductible IRA, HSA).
    AGI: Adjusted Gross Income = Gross Income − Adjustments (not below zero).
    Deduction: Either the MFJ standard deduction for the year or your itemized total.
    Taxable Income: AGI − Deduction (not below zero).
    Marginal Rate: The bracket rate applied to your next dollar of taxable income.
    Effective Rate: Total tax divided by Gross Income.
    Bracket Breakdown: Portion of taxable income taxed at each marginal rate.

    How It Works: A Step-By-Step Example

    Inputs:

    Computation:

    1. AGI = 120,000 − 5,000 = $115,000
    2. Taxable Income = 115,000 − 29,200 = $85,800
    3. Apply brackets (MFJ 2024):
      • 10% on $23,200 → $2,320
      • 12% on $62,600 − $23,200 = $39,400 (but taxable is $85,800, which is below the 12% cap $94,300) → 0.12 × $62,600? Wait; Re-evaluate strictly by layers:

    For clarity, the calculator performs the summation programmatically per the formula above and shows the bracket-by-bracket breakdown in Results. Try the same inputs to see the exact distribution and totals.

    This worked example is an illustration. Your actual tax may differ based on credits, special rules, or additional income types.

    Frequently Asked Questions (FAQ)

    Does this calculator include tax credits?

    No. It estimates federal income tax before credits such as the Child Tax Credit, American Opportunity Credit, or Saver’s Credit.

    Which filing status is supported?

    This page focuses on Married Filing Jointly (MFJ). Use status-specific tools for other filing statuses.

    Which years are supported?

    Tax years 2023 and 2024, using IRS-published inflation-adjusted brackets and the standard deduction for each year.

    What if my itemized deductions are lower than the standard deduction?

    You can still select Itemized, but most households will benefit from the higher standard deduction. The calculator will use whichever option you select.

    How is the effective tax rate calculated?

    Effective rate = total federal income tax ÷ gross income. If gross income is zero, it is reported as 0%.

    Does this include long-term capital gains or qualified dividends?

    No. This version focuses on ordinary income. If those apply to you, consider a calculator that handles preferential rates for those categories.

    Is this tax, legal, or financial advice?

    No. This tool is for educational estimates only. Consult a qualified professional for advice tailored to your situation.