Article — FICA Tax Calculator
FICA tax calculator: Social Security plus Medicare
FICA tax is the federal payroll tax that funds Social Security and Medicare. Employees pay 6.2% Social Security up to the annual wage base ($168,600 in 2024) plus 1.45% Medicare on all wages, and employers match. High earners owe an additional 0.9% Medicare surtax with no employer match. The FICA tax calculator on this page applies the IRS and Social Security Administration figures and supports both W-2 employee and self-employed (SECA) modes.
FICA stands for the Federal Insurance Contributions Act. It is a separate tax from federal income tax — those are two distinct deductions on a U.S. pay stub.
What FICA tax funds
FICA collections feed two trust funds. The Old-Age, Survivors, and Disability Insurance (OASDI) trust fund pays retirement, survivor, and disability benefits under Social Security. The Hospital Insurance (HI) trust fund pays Medicare Part A hospital benefits. The Social Security Administration and the Centers for Medicare & Medicaid Services jointly publish the trust-fund accounting.
FICA does not fund Medicaid, Part B premiums, federal income tax obligations, or state programs. Those flow from general revenues and other dedicated taxes.
The three FICA tax rates
The rates have been stable for decades; only the Social Security wage base moves with national average wages.
Social Security 6.2% to $168,600Medicare 1.45% on all wagesAdditional Medicare 0.9% above filing thresholdEmployers match the first two lines: 6.2% Social Security to the wage base and 1.45% Medicare on all wages. Combined employer and employee rates are 12.4% and 2.9%. The 0.9% additional Medicare tax falls on the employee only — the employer does not match it.
The Social Security wage base
The Social Security Administration adjusts the wage base each year in line with the national average wage index. Once year-to-date wages from a single employer cross the base, that employer stops withholding the 6.2% for the rest of the year. Medicare withholding continues unchanged.
- 2024 base = $168,600 (Social Security Administration)
- 2023 base = $160,200
- 2022 base = $147,000
- 2021 base = $142,800
- Maximum employee Social Security tax in 2024 = $168,600 × 6.2% = $10,453.20
- Combined employer + employee maximum = $20,906.40 per worker
The Social Security wage base has risen every year since 1973 except 2010, when the national average wage index dropped during the financial crisis. Medicare has had no wage cap since 1994, when Congress removed it under the Omnibus Budget Reconciliation Act of 1993.
The 0.9% Additional Medicare tax
The Additional Medicare Tax took effect in 2013 under the Affordable Care Act. It applies an extra 0.9% Medicare withholding on wages above a filing-status threshold:
- Single, head of household, qualifying surviving spouse = $200,000
- Married filing jointly = $250,000
- Married filing separately = $125,000
Employers withhold the 0.9% once an individual employee's year-to-date wages from that employer pass $200,000, even before the household-level threshold can be evaluated. Final reconciliation happens on Form 8959 with the IRS Form 1040 tax return — overwithheld amounts come back as a refund, underwithheld amounts are paid with the return.
FICA tax for self-employed workers
Self-employed workers pay both halves of FICA under the Self-Employment Contributions Act (SECA). The math has two extra steps. First, net earnings from self-employment are multiplied by 0.9235 — the employer-equivalent portion is treated as not subject to SE tax. Second, the doubled rates apply: 12.4% Social Security to the wage base and 2.9% Medicare on the entire adjusted base.
SE base = Net earnings × 0.9235SE tax = SE base × 12.4% (to wage base) + SE base × 2.9%The deductible portion is the employer-equivalent half of the SE tax. It flows to Schedule 1 of Form 1040 and reduces adjusted gross income. It does not reduce SE tax itself — only the income tax that flows from AGI.
Each employer applies the wage base independently. If you worked for two employers and your combined wages crossed $168,600 in 2024, you almost certainly paid more Social Security than the cap allows. Claim the excess as a credit on Schedule 3, line 11 of Form 1040 — the IRS will not refund it automatically.
Worked FICA tax examples
Three scenarios show how the FICA tax components combine.
$60,000 W-2 employee, single, 2024. Social Security = 60,000 × 6.2% = $3,720. Medicare = 60,000 × 1.45% = $870. Additional Medicare = $0 (under $200,000). Total employee FICA = $4,590, an effective rate of 7.65%. The employer matches with another $4,590; combined cost is $9,180.
$250,000 W-2 employee, single, 2024. Social Security = 168,600 × 6.2% = $10,453.20 (wage-base capped). Medicare = 250,000 × 1.45% = $3,625. Additional Medicare = (250,000 − 200,000) × 0.9% = $450. Total employee FICA = $14,528.20, effective rate 5.81%. The employer pays the matched portion of $14,078.20, but not the $450 surtax.
$100,000 self-employed net earnings, 2024. SE base = 100,000 × 0.9235 = $92,350. Social Security portion = 92,350 × 12.4% = $11,451.40. Medicare portion = 92,350 × 2.9% = $2,678.15. Total SE tax = $14,129.55, effective rate 14.13%. The deductible employer-equivalent half ($7,064.78) reduces adjusted gross income on Form 1040.
Common FICA tax mistakes
Mistake one: confusing FICA with federal income tax. FICA is a flat percentage with no brackets or standard deduction. Income tax uses brackets that range from 10% to 37% in 2024 and is reduced by the standard deduction or itemised deductions.
Mistake two: treating 401(k) contributions as FICA-exempt. Traditional pre-tax 401(k) deferrals reduce taxable wages for federal income tax but still count as wages for Social Security and Medicare. Roth 401(k) contributions are after-tax and therefore have no effect on either tax.
If you change jobs mid-year and your combined wages will exceed the Social Security wage base, your new employer cannot stop withholding early — they only see their own payroll. Track the cap yourself and claim the excess as a credit at tax time using IRS Schedule 3.
Mistake three: forgetting that the 0.9% Additional Medicare tax has no employer match and no annual cap. Mistake four: assuming self-employed people pay 15.3% on every dollar — the 92.35% adjustment and the wage-base cap on the Social Security component both lower the effective rate.