Article L.211-27 of the Labour Code provides that “The hourly wage is obtained by dividing monthly wages by the flat rate of one hundred and seventy-three hours”.
Thus, the wage to be taken into account for calculation of the hourly wage is the monthly wage or the hourly wage stipulated in the employment contract and as resulting from the salary slips.
The legal provisions do not require overtime to be remunerated on the basis of an average of gross wages or salaries paid to the employee.
Also, the fact of including, where appropriate, a 13th month is not covered by legal provisions.
Example
An employee receives a salary of € 3,000 under his employment contract, as recorded in his salary slips.
The hourly wage thus amounts to € 3,000 ÷ 173 = € 17.34.
So far as concerns payment for overtime, the normal hourly wage is increased by 40% and amounts to (17.34 + 6.94) = € 24.28.
If the employee has worked 4 additional hours during a month, the 4 hours must be multiplied by the increased hourly rate of € 24.28 = € 97.12 (for those 4 additional hours).
For cases where the working of overtime is paid for in the form of compensatory rest, those 4 hours must be multiplied by 1.5 = 6 hours remunerated compensatory rest.