Social Security Tax Calculator

Updated August 2026 · Free · No sign-up

Calculate Social Security (OASDI) tax: the 6.2% rate, the annual wage base cap, the employer match, when withholding stops for high earners — and how to reclaim over-withholding from multiple jobs.

How Social Security Tax Works

OASDI (Old-Age, Survivors, and Disability Insurance) — the "Social Security" line on your paystub — takes 6.2% of wages up to an annual wage base, with an equal employer match. Two defining features:

• The cap: once year-to-date wages hit the wage base, withholding stops — high earners see paychecks grow late in the year. The base rises with national wage growth nearly every January.
• Benefits linkage: capped taxes fund capped benefits — your eventual Social Security benefit is computed from earnings up to the same base, which is the policy logic for the cap's existence (and the debate about lifting it).

Worked Examples

Example 1 — under the cap. $85,000: 6.2% = $5,270 employee-side, matched by the employer — $10,540 total into OASDI.

Example 2 — over the cap. $220,000 with a $176,100 base: tax applies to the base only → $10,918; the last ~$43,900 of salary pays zero OASDI. Withholding stops mid-November for an even payroll.

Example 3 — two jobs, one refund. $110,000 at job A + $90,000 at job B: each employer withholds on its own wages ($6,820 + $5,580 = $12,400) — but the personal cap is $10,918. The ~$1,482 excess comes back as a credit on your tax return (Schedule 3). Employers can't coordinate; only your 1040 fixes it.

OASDI at a Glance

What Counts as OASDI Wages

Nearly all compensation: salary, hourly wages, bonuses, commissions, severance (settled by the Supreme Court's Quality Stores case), PTO payouts, and stock compensation at vest — all up to the cap. The reducers mirror Medicare's short list: Section 125 health premiums, FSA, and payroll HSA contributions. 401(k) deferrals do NOT reduce OASDI wages — a persistent myth; your Social Security earnings record (and eventual benefit) is unaffected by 401(k) saving.

The Cap in Practice: Planning Notes

• Late-year lump sums: a bonus or severance paid after you've crossed the base correctly skips the 6.2% — verify payroll actually skipped it (see the severance tax calculator and bonus tax calculator, both of which ask this question).
• Job changes mid-year: the new employer must withhold from zero — the cap is per-employer in withholding, personal at filing. Expect the Schedule 3 credit, not a payroll fix.
• The paycheck bump: crossing the cap raises take-home ~6.2% for the rest of the year — a known budgeting rhythm for high earners (and a January "pay cut" when it resets).
• Paystub audit: OASDI should equal exactly 6.2% of FICA-taxable YTD wages until the base, then freeze. Anything else is a payroll error worth an email.

Self-Employed: SECA's Social Security Half

Schedule SE applies 12.4% to 92.35% of net self-employment earnings up to the wage base — the single biggest tax-rate shock of going freelance (a W-2 employee never sees the employer 6.2%). Half is deductible above-the-line, and mixed years (W-2 + 1099) apply W-2 wages against the cap first — often shrinking the SECA Social Security bill for moonlighters. Rate-setting freelancers: the ~7.65% total FICA differential belongs in your rate conversion.

OASDI vs the Rest of FICA

OASDI (6.2%, capped) + Medicare (1.45%, uncapped, surtaxed above $200k) = FICA's 7.65%. Their opposite structures — one stops for high earners, the other escalates — are why paystubs list them separately. The combined view with employer costs lives in the FICA payroll tax calculator and the employer payroll tax calculator.

✓ Formula verified  •  Last updated: August 20, 2026