Taxable Social Security Calculator
Up to 85% of your Social Security benefits can be included in your federal taxable income, depending on your provisional income. This calculator follows the IRS Publication 915 worksheet: it computes provisional income from your other income, tax-exempt interest and half your benefits, compares it to the statutory base amounts for your filing status, and returns the taxable portion (capped at 85% of benefits). The base amounts are fixed in law and not inflation-indexed; they are editable inputs preset to the standard values.
IRS Publication 915 worksheet (summary)
Provisional income = other income + tax-exempt interest + 50% of benefits If provisional <= lower base: taxable = 0 If between bases: taxable = min(50% of benefits, 50% of (provisional - lower base)) If above upper base: taxable = min(85% of benefits, 0.85 x (provisional - upper base) + smaller of [prior 50% result] and [50% of (upper base - lower base)])
The taxable amount can never exceed 85% of benefits.
Worked example
Joint filer, benefits 24,000, other income 30,000, no exempt interest. Provisional = 30,000 + 12,000 = 42,000, between 32,000 and 44,000. Taxable = min(12,000, 50% of 10,000) = 5,000.00.
Taxable Social Security: frequently asked questions
How much of my Social Security is taxable?
It depends on your provisional income: your other income plus tax-exempt interest plus half of your Social Security benefits. If provisional income is below the first base amount, none of your benefits are taxable. Between the two base amounts, up to 50% is taxable. Above the upper base amount, up to 85% is taxable. This calculator follows the IRS Publication 915 worksheet.
What are the base amounts?
The base amounts are fixed in the Internal Revenue Code and are not adjusted for inflation. For single filers the lower base is 25,000 and the upper base is 34,000; for married filing jointly they are 32,000 and 44,000. Because they are statutory, this calculator provides them as editable inputs preset to the long-standing values; confirm them in Publication 915.
What is provisional income?
Provisional income (the IRS worksheet calls it modified income plus half of benefits) equals your adjusted gross income excluding Social Security, plus any tax-exempt interest, plus 50% of your Social Security benefits. It is the figure compared against the base amounts to decide how much of your benefits are taxable.
Is 85% the most that can be taxed?
Yes. At most 85% of your Social Security benefits are included in taxable income; the remaining 15% is never taxed at the federal level. The exact taxable amount is the smaller of 85% of benefits and a worksheet figure based on how far your provisional income exceeds the base amounts.
Official sources
- Internal Revenue Service: About Publication 915, Social Security and Equivalent Railroad Retirement Benefits.
- Social Security Administration: Income Taxes And Your Social Security Benefit.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.