Social Security Benefits Tax Calculator

Is your Social Security taxable, and what does your next dollar of income really cost?

Up to 50% then 85% of your benefits are taxed once your provisional income (other income plus half your benefits) passes $25,000 single or $32,000 joint, and $34,000 or $44,000. Enter your figures to see the taxable share, the tax, and the effective rate on an extra IRA withdrawal or Roth conversion (the "tax torpedo").

The numbers stay in this browser tab. It does arithmetic on what you type; it is a worksheet, not advice. The base amounts are not indexed for inflation.

Your income

Filing status

Total Social Security benefits for the year, dollars (SSA-1099 box 5)

Other income, dollars (wages, pension, IRA withdrawals, interest, gains, tax-exempt interest)

Your marginal federal tax rate, percent

First base amount, dollars (blank = default for status)

Second base amount, dollars (blank = default for status)

Fill in the figures, then click Work out the taxable benefits.

Result

If your other income were higher or lower

Other income	Provisional income	Taxable benefits	% of benefits	Tax on them

Benefits are held at the figure you entered; the tax column uses your single marginal rate, so it is rough across large changes.

What it does, and what it leaves to you

Counts: provisional income = other income + half of benefits; taxable benefits per the IRS Publication 915 worksheet, capped at 85% of benefits; the tax at the marginal rate you enter; and the effective rate on the next $1,000 of income.
Not decided: your exact adjusted gross income, deductions, credits, state tax, the lump-sum election, Medicare IRMAA surcharges, and whether any withdrawal or conversion is right for you.

Common questions

How is Social Security taxed?

Up to 50% or 85% of your benefits can be included in taxable income, depending on your provisional income: your other income (including tax-exempt interest) plus half of your benefits. At or under $25,000 single or $32,000 married filing jointly none is taxable. Between the two bases up to 50% is. Above $34,000 single or $44,000 joint up to 85% is. It is a share of benefits that gets taxed, not a tax rate.

What is the tax torpedo?

In the zone where taxable benefits are rising, each extra dollar of income (an IRA withdrawal, a Roth conversion, a capital gain) also makes up to 85 cents more of your benefits taxable, so it is taxed as up to $1.85. At a 22% bracket that is an effective 40.7% on the next dollar. Above the 85% ceiling the effect stops.

Do the $25,000 and $32,000 bases rise with inflation?

No. They were set in 1984 and 1993 and are not indexed, so more retirees cross them every year. This calculator lets you edit both bases in case the law changes.

What counts as other income?

Adjusted gross income without the benefits (wages, pensions, IRA and 401(k) withdrawals, interest, dividends, capital gains, rental and self-employment income) plus tax-exempt interest. Roth IRA withdrawals that are qualified are not income.

Does this include state tax?

No. It is the federal worksheet only. Most states do not tax Social Security, but a few do under their own rules.

Does this tell me what to do?

No. It is a worksheet that does arithmetic on the figures you enter. Check IRS Publication 915 or a tax professional before changing a withdrawal plan.

Is my data uploaded anywhere?

No. Everything is worked out in your browser and nothing is sent; a test in the code asserts there are no network calls.