Social Security Tax Torpedo Calculator United States

What the tax torpedo calculator does

Many retirees assume their marginal tax rate matches their bracket. Because extra income can make more of their Social Security taxable, it often does not. Enter your filing status, your annual Social Security benefits and your other taxable income, such as pensions, IRA withdrawals or wages. The calculator works through the IRS provisional-income worksheet to show how much of your Social Security is taxable, your federal tax, and the true marginal rate on the next dollar of ordinary income. When that rate is well above your bracket, you are in the torpedo.

How Social Security becomes taxable

Benefits are not always taxed, and never in full. The IRS uses provisional income, sometimes called combined income:

• Provisional income equals your other taxable income, plus any tax-exempt interest, plus one half of your Social Security benefits.
• Below the first threshold, none of your benefits are taxable.
• Between the first and second thresholds, up to 50 percent of benefits become taxable.
• Above the second threshold, up to 85 percent of benefits become taxable.

The thresholds depend on filing status. Ordinary income counts dollar for dollar toward provisional income, so adding income can move you through both thresholds and make more of your benefits taxable.

Why the torpedo raises your marginal rate

In the tier where each additional dollar of income makes 85 cents of benefits taxable, a 12 percent bracket taxes the extra dollar at 12 percent and the 85 cents of newly taxable benefits at 12 percent too. The combined rate is about 12 percent times 1.85, or roughly 22.2 percent, on that dollar.

In the 22 percent bracket the true rate can reach about 40.7 percent. A modest IRA withdrawal or small capital gain in this range can carry a surprisingly large tax cost. The calculator measures it by comparing your tax before and after a small increase in ordinary income.

Reading your result

The main output is the true marginal rate on your next dollar of ordinary income, shown next to your statutory bracket rate. The calculator also reports your provisional income, the dollar amount and percentage of benefits that are taxable, your taxable income after the standard deduction, and your estimated federal tax.

If the true rate is close to your bracket rate, you are outside the torpedo and extra income is taxed roughly as expected. If it is far higher, you are inside it, and realizing extra income in this range is expensive. The doughnut chart splits your benefits into taxable and tax-free portions, showing the 85 percent ceiling.

Planning around the torpedo

Most strategies aim to spread income across years instead of concentrating it. Retirees often discuss with advisors converting part of a traditional IRA to a Roth in lower-income years, before benefits begin or early in retirement, so later withdrawals do not keep pushing benefits into the taxable tiers. Others time large IRA withdrawals so they do not stack on other income in one year, manage capital gains and other irregular income so it does not tip provisional income across a threshold, or coordinate when benefits start with other income sources.

The right approach depends on your full finances, including future required minimum distributions. The calculator tells you whether you are in the torpedo and how steep it is, which is where any of these conversations starts.

Limitations

The tool estimates federal income tax on Social Security using the standard provisional-income rules and the federal brackets and standard deduction for your filing status. It does not model state taxes on benefits, which a handful of states levy, or every credit, deduction or income type that could affect your return. It treats your inputs as annual totals for one tax year. Thresholds and brackets can change, so rerun it when your income shifts or a new tax year begins, and confirm decisions with real tax consequences with a qualified tax professional.

This is general information only and not financial or tax advice.

About This Tool: Social Security Tax Torpedo

Social Security tax torpedo: use this tool to get an instant, accurate estimate. The figures follow official IRS guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.