Social Security tax is 6.2% of your wages, taken from your paycheck up to an annual earnings cap

Your employer withholds Social Security tax automatically from each paycheck. The rate is 6.2% of your gross wages — the amount before taxes and deductions. This continues until your earnings for the year reach a cap, which changes annually. Once you hit that cap, no more Social Security tax comes out for the rest of that year.

Your employer also pays a matching 6.2%, but that does not affect your calculation. If you are self-employed, you pay both sides yourself — 12.4% total — though you can deduct half of it on your tax return.

The earnings cap for 2024 is $168,600. For 2025, it is $176,100. These numbers rise each year based on wage growth. You can find the current year's cap on the Social Security Administration website or your pay stub.

Key Takeaways

  • Social Security tax is 6.2% of your wages, withheld by your employer until you reach the annual earnings cap.
  • The earnings cap changes each year — for 2024 it is $168,600, and for 2025 it is $176,100.
  • Once your year-to-date earnings hit the cap, your employer stops withholding Social Security tax for the rest of that year.
  • If you change jobs mid-year, you may overpay Social Security tax and can claim the overage as a credit on your tax return.
  • Self-employed workers pay 12.4% total Social Security tax on net earnings, though they can deduct half on their return.

The basic calculation: 6.2% of gross wages

To calculate your Social Security tax on a single paycheck, multiply your gross pay by 0.062. Gross pay is your salary or hourly wage before any deductions — before federal income tax, health insurance, retirement contributions, or anything else comes out.

Example: If you earn $2,000 in a paycheck, your Social Security tax is $2,000 × 0.062 = $124.

Your pay stub will show this amount on the line labeled "Social Security" or "OASDI" (Old-Age, Survivors, and Disability Insurance). You do not need to calculate it yourself — your payroll department does it. But knowing the formula helps you spot errors or understand why your take-home pay changes.

How the annual earnings cap works

Social Security tax only applies to earnings up to a cap. Once you earn that amount in a calendar year, your employer stops withholding Social Security tax from your remaining paychecks for that year. This is different from Medicare tax, which has no cap and continues all year.

For 2024, the cap is $168,600. This means if you earn $168,600 or more in 2024, you will pay Social Security tax on exactly $168,600 and nothing more. If you earn $200,000, you still only pay on $168,600.

Your employer tracks your year-to-date earnings and stops the withholding automatically. You will see "Social Security tax" disappear from your pay stub once you cross the cap, though Medicare tax and income tax withholding continue.

What happens if you change jobs mid-year

If you work for two employers in the same year, each one withholds Social Security tax independently. Neither employer knows what you earned at the other job. This can lead to overpayment.

Example: You earn $100,000 at Job A, then leave and earn $80,000 at Job B. Job A withheld Social Security tax on $100,000. Job B withheld it on $80,000. Your total earnings are $180,000, but the cap is $168,600. You overpaid by $180,000 − $168,600 = $11,400 in earnings subject to tax, or $11,400 × 0.062 = $706.80 in excess Social Security tax.

When you file your tax return, you claim this overpayment as a credit. The IRS compares your total earnings across all employers to the cap and refunds the difference. You do not need to contact your employers — the tax return handles it automatically.

Self-employed Social Security tax calculation

If you are self-employed, you pay both the employee and employer portions of Social Security tax. The combined rate is 12.4%. You calculate it on your net self-employment income — your business income minus business expenses — not your gross revenue.

You report self-employment income on Schedule C (if you are a sole proprietor) or your business return. Then you calculate self-employment tax on Schedule SE. The formula is: net self-employment income × 0.9235 × 0.124 = self-employment tax. The 0.9235 factor accounts for the fact that you can deduct half your self-employment tax as a business expense.

Example: Your net self-employment income is $60,000. Your self-employment tax is $60,000 × 0.9235 × 0.124 = $6,878.64. You pay this when you file your return or in quarterly estimated tax payments.

The annual earnings cap applies to self-employed workers too. Once your net self-employment income reaches the cap, you stop calculating the 12.4% Social Security portion, though you continue paying 2.9% Medicare tax on all earnings.

Reading your pay stub to verify the calculation

Your pay stub shows Social Security tax withheld under a line labeled "Social Security," "OASDI," or "SS." Next to it you should see the amount withheld and often your year-to-date total. Check that the amount withheld matches 6.2% of your gross pay.

If your year-to-date Social Security tax stops increasing mid-year while your paychecks continue, that is correct — you have hit the cap. If it continues rising after you reach the cap, contact your payroll department. This is rare but can happen if your employer's system has a glitch.

You should also see a separate line for Medicare tax, which is 1.45% of gross pay with no cap. Together, Social Security and Medicare make up your FICA taxes (Federal Insurance Contributions Act).

Why the cap exists and how it affects high earners

The earnings cap exists because Social Security benefits are capped. Higher earners do not receive proportionally higher benefits, so the program does not tax earnings above the cap. This makes Social Security a regressive tax — lower earners pay a higher percentage of their total income.

High earners benefit from the cap. Once you reach it, every additional dollar you earn that year is not subject to Social Security tax. Lower earners pay on every dollar they make. The cap also means that if you earn $200,000 and someone else earns $500,000, you both pay the same total Social Security tax for the year.

The cap is indexed to wage growth, so it rises most years. This means more earnings become subject to Social Security tax over time, though the 6.2% rate itself has not changed since 1990.

Frequently Asked Questions

Can I opt out of Social Security tax?

No. Social Security tax is mandatory for all employees and self-employed workers. The only exception is certain government employees hired before specific dates who are covered by different pension systems, but this is rare and determined by your employer, not by choice.

What if my employer did not withhold Social Security tax?

Contact your payroll department when ready. This is usually a payroll system error. If your employer intentionally did not withhold, you are still liable for the tax and may owe it when you file your return. The IRS can also pursue your employer for the unpaid withholding.

Does Social Security tax explore to bonuses and overtime?

Yes. Social Security tax applies to all wages, including bonuses, overtime pay, and commissions. The 6.2% rate applies to the total, and the annual cap still governs when withholding stops.

If I work part-time at two jobs, do I pay Social Security tax twice?

Yes, but only up to the annual cap across both jobs combined. Each employer withholds independently, which can cause overpayment. You claim the overage as a credit when you file your tax return.

How do I know if I have reached the Social Security tax cap?

Check your pay stub. Once you reach the cap, the Social Security tax line will show $0 withheld, though Medicare tax continues. Your year-to-date Social Security tax total will also stop increasing. You can verify the cap amount on the Social Security Administration website each January.