Free federal estimate
Social Security Tax Calculator
Estimate how much of your Social Security benefit is included in federal taxable income using the IRS combined-income formula.
Combined income
$40,000
Estimated taxable benefits
$4,000
Share of benefits taxable
13.3%
Your thresholds are $32,000 and $44,000 of combined income. The calculator estimates the amount included in federal taxable income—not your final tax bill.
Married filing separately has special rules and is intentionally excluded. Use IRS Publication 915 or a qualified tax professional for that filing status, lump-sum elections, railroad retirement benefits, or complex adjustments.
How the estimate works
The IRS starts with combined income: adjusted gross income plus tax-exempt interest plus half of annual Social Security benefits. It then applies two thresholds based on filing status. The result is the amount of benefits included in taxable income—not the tax owed on that amount.
This calculator implements the worksheet logic from IRS Publication 915. The statutory thresholds are not indexed for inflation, but unusual filing statuses, lump-sum elections, and railroad benefits require the full worksheet.
What the calculator does not estimate
It does not calculate total federal tax, state tax, Medicare IRMAA surcharges, deductions, credits, or married-filing-separately special rules. Use the output as a planning estimate and confirm a filing decision with current IRS guidance or a qualified tax professional.
For a complete explanation, read How Social Security Is Taxed and the guide to spousal and survivor benefits.