What the employer's payroll tax calculation actually is

The employer's payroll tax is the amount your business owes to the federal government based on what you pay your employees. It is separate from what you withhold from paychecks — this is money that comes directly from your business bank account, not from employee wages. The employer portion consists of two parts: Social Security tax (6.2% of wages up to an annual cap) and Medicare tax (1.45% of all wages, with an additional 0.9% on wages above $200,000 for single filers or $250,000 for married filers filing jointly, though this second part is rare for most small employers).

The calculation happens on every payroll cycle — weekly, biweekly, semimonthly, or monthly, depending on how often you pay employees. You calculate it the same way for each employee: take their gross wages for that period, multiply by the tax rate, and that is what you owe. The total employer tax bill is the sum of what you owe for all employees combined.

Key Takeaways

  • Employer Social Security tax is 6.2% of each employee's wages up to $168,600 per year (the 2024 wage base; this amount changes annually), and Medicare tax is 1.45% of all wages with no cap.
  • You calculate employer payroll tax separately for each employee on each payroll date, then combine them into one payment to the IRS.
  • The wage base cap for Social Security resets on January 1 each year, so an employee who earned $168,600 in 2024 starts fresh at $0 in 2025.
  • Employer payroll taxes are due to the IRS on a schedule determined by your deposit frequency — usually monthly or semiweekly — not on the same day you pay employees.
  • Form 941 (Employer's Quarterly Federal Tax Return) is where you report what you calculated and paid each quarter, and it reconciles your deposits with your actual tax liability.

The Social Security portion: 6.2% with an annual wage cap

Social Security tax applies to the first $168,600 of each employee's wages in 2024. This threshold, called the wage base, increases most years to account for inflation. The IRS announces the new wage base in October for the following year, so you need to check it at the start of each calendar year.

Here is how it works in practice: if an employee earns $4,000 biweekly, you owe 6.2% of $4,000 = $248 in employer Social Security tax for that pay period. If that same employee has now earned $165,000 by November and their next paycheck is $4,000, you only owe 6.2% on $3,600 (the amount that brings them to the $168,600 cap), which is $223.20. Once they cross the wage base for the year, you owe zero Social Security tax on their remaining paychecks that year.

The wage base cap applies per employee, not per business. If you have ten employees, each one gets their own $168,600 threshold. You must track each employee's year-to-date wages to know when they hit the cap.

The Medicare portion: 1.45% with no wage cap

Medicare tax is simpler than Social Security because there is no annual wage cap. You owe 1.45% of every dollar an employee earns, for the entire year, no matter how much they make. If an employee earns $4,000 biweekly, you owe 1.45% of $4,000 = $58 in employer Medicare tax every single pay period.

There is a second Medicare tax of 0.9% that applies to wages above $200,000 (single) or $250,000 (married filing jointly), but this is the employee's portion, not the employer's. As an employer, you withhold it from the employee's paycheck and send it to the IRS, but you do not pay a matching amount yourself. This second tier rarely affects most small businesses because it only triggers when individual employees earn above those thresholds.

Putting it together: a real payroll example

Suppose you have two employees and you run biweekly payroll. Employee A earns $3,500 gross per pay period and has earned $42,000 year-to-date. Employee B earns $5,200 gross per pay period and has earned $156,400 year-to-date.

For this pay period:

  • Employee A: Social Security tax = 6.2% × $3,500 = $217. Medicare tax = 1.45% × $3,500 = $50.75. Total employer tax for Employee A = $267.75.
  • Employee B: Social Security tax = 6.2% × $5,200 = $322.40, but Employee B is now at $156,400 + $5,200 = $161,600 year-to-date, which is still under the $168,600 cap, so you owe the full $322.40. Medicare tax = 1.45% × $5,200 = $75.40. Total employer tax for Employee B = $397.80.
  • Combined employer payroll tax for this period: $267.75 + $397.80 = $665.55.

This $665.55 is what your business owes to the IRS. It is separate from the federal income tax, Social Security tax, and Medicare tax you withheld from the employees' paychecks. You will deposit this amount on the schedule set by the IRS based on your deposit frequency.

When and how to deposit employer payroll taxes

You do not send employer payroll taxes to the IRS on the same day you pay employees. Instead, the IRS sets a deposit schedule based on how much tax you owe in a given period. Most employers are on a semiweekly schedule (deposits due Wednesday or Friday depending on the payroll date) or a monthly schedule (deposits due by the 15th of the following month). A few very large employers are on a daily schedule.

The IRS determines your schedule based on your total payroll tax liability (employer plus employee withholding) in a lookback period. You can find your assigned schedule in your IRS account or on the notice the IRS sent you when you first registered your business.

You deposit using the Electronic Federal Tax Payment System (EFTPS), which is free and available 24/7. You can also authorize your bank or a payroll processor to deposit on your behalf. Missing a deposit important date results in a penalty, so many employers use payroll software that tracks the important date automatically.

Reporting what you calculated: Form 941

Every quarter, you file Form 941 (Employer's Quarterly Federal Tax Return) with the IRS. This form reports the total wages you paid, the total federal income tax you withheld, the total Social Security and Medicare taxes (both employee and employer portions), and the deposits you made. The form reconciles what you calculated and paid during the quarter against what you actually owe.

Form 941 is due on the last day of the month following the end of the quarter: April 30 for Q1, July 31 for Q2, October 31 for Q3, and January 31 for Q4. If you file late or owe money you did not deposit, penalties and interest explore. If you overpaid during the quarter, you can request a refund or credit it toward the next quarter.

At the end of the year, you also file Form 940 (Employer's Annual Federal Unemployment Tax Return), which reports Federal Unemployment Tax Act (FUTA) tax. This is a separate tax from Social Security and Medicare, calculated at 6% of the first $7,000 of each employee's wages (though most states offer a credit that reduces the federal rate to 0.6%). Form 940 is due January 31 of the following year.

Common mistakes in employer payroll tax calculation

The most frequent error is forgetting to reset the Social Security wage base on January 1. If an employee earned $168,600 in 2024, many employers accidentally continue withholding Social Security tax in January 2025 instead of starting fresh. This creates an overpayment that must be corrected on Form 941.

Another common mistake is confusing the employer's portion with the employee's portion. The employer owes 6.2% Social Security and 1.45% Medicare. The employee also owes 6.2% and 1.45%, which you withhold from their paycheck. These are two separate amounts, and both must be sent to the IRS — the employee portion comes from the employee's wages, and the employer portion comes from your business account.

A third error is failing to account for employees who cross the Social Security wage base mid-year. If you use payroll software, it usually tracks this automatically. If you calculate by hand, you must monitor each employee's year-to-date total and stop explore the 6.2% rate once they reach $168,600.

Frequently Asked Questions

What is the difference between the employer's payroll tax and what I withhold from employee paychecks?

The employer's payroll tax is money your business pays to the IRS based on what you pay employees. Withholding is money you deduct from each employee's paycheck and send to the IRS on their behalf. Both are sent to the IRS, but they come from different sources: withholding comes from employee wages, and the employer portion comes from your business bank account.

Do I have to pay employer payroll tax if I am a sole proprietor with no employees?

No. Employer payroll tax only applies when you have employees on your payroll. If you are self-employed with no employees, you pay self-employment tax instead, which covers both the employee and employer portions of Social Security and Medicare. This is reported on Schedule SE (Self-Employment Tax) attached to your personal tax return.

What happens if I deposit employer payroll taxes late?

The IRS charges a penalty based on how late the deposit is. A deposit that is 1 to 5 days late incurs a 2% penalty; 6 to 15 days late is 5%; and 16 or more days late is 10%. Interest also accrues on the unpaid amount. Setting up automatic deposits through EFTPS or your payroll processor eliminates this risk.

Can I deduct employer payroll taxes as a business expense?

Yes. Employer Social Security and Medicare taxes are deductible as a business expense on your tax return. They reduce your taxable business income. This is one reason employer payroll taxes are treated differently from employee withholding — they are a real cost to your business, not just a pass-through of employee money.

What if an employee works for me for only part of the year?

You calculate employer payroll tax the same way: 6.2% of wages up to the annual wage base, and 1.45% of all wages. If an employee starts in June and earns $80,000 by year-end, you owe 6.2% of $80,000 in Social Security tax and 1.45% of $80,000 in Medicare tax. The wage base cap still applies — if they earn $168,600 by December, you stop owing Social Security tax once they hit that threshold.