It's the same as why you wouldn't measure your weight in ounces, but neither would you weigh something very light in pounds - you want a convenient number which is easy to interpret. PC is short for parsec and it's a unit of measurement equal to 3,000,000,000,000,000,000 cm!
Take your annual covered earnings (the earnings on which you pay Social Security payroll taxes), multiply it by that year's index factor and you will obtain your indexed wage for each year you have worked. Next, add up all these indexed wages and divide them by 35 to determine your average wage.
3. Multiply the employee rate by the employee's wages to find the amount the company must withhold from the employee's paycheck for Social Security taxes. For example, if the employee's monthly pay equals $3,170, multiply $3,710 by 0.042 to find the company must withhold $133.14 for Social Security taxes. 4. Multiply the employer rate by the employee's pay to find the amount the company must pay to the government in employer Social Security taxes because of the payment to the employee. In this example, multiply 0.062 by $3,170 to find the company has to pay $196.54 in employer Social Security taxes.