Calculate the sum of all assessed taxes, including Social Security, Medicare and federal and state withholding information found on a W-4. Divide this number by the gross pay to determine the percentage of taxes taken out of a paycheck.

Multiply the hourly wage by the number of hours worked per week. Then, multiply that number by the total number of weeks in a year (52). For example, if an employee makes $25 per hour and works 40 hours per week, the annual salary is 25 x 40 x 52 = $52,000.

First, determine the total number of hours worked by multiplying the hours per week by the number of weeks in a year (52). Next, divide this number from the annual salary. For example, if an employee has a salary of $50,000 and works 40 hours per week, the hourly rate is $50,000/2,080 (40 x 52) = $24.04.