What is the rate upon which overtime must be calculated and paid?

Overtime must be paid at one and one-half times an employee’s regular rate of pay for each hour worked in excess of 40 hours per week.

Overtime is based on the regular rate of pay, which is the compensation you normally earn for the work you do. The regular rate of pay may include several different kinds of compensation, such as hourly earnings, salary, piecework earnings, and commissions. The regular rate of pay cannot be less than the applicable minimum wage. Ordinarily, the hours to be used in computing the regular rate of pay may not exceed the legal maximum regular hours which, in most cases, is 8 hours per workday, 40 hours per workweek.

If you are paid on an hourly basis, that amount is the regular rate of pay. If you are paid with a salary, your salary must be converted to a workweek equivalent. For example, a month salary would be multiplied by 12 (no. of months in a year) and divided by 52 (no. of weeks in a year).