as Salam mu alaikum

Upon the legal termination of the employment contract, you are entitled to receive an end of service gratuity
The end of service gratuity is calculated at the rate of fifteen days' salary for each year of service of the first five years.
And a month’s salary for each year of service in excess of that.
Here is the text of the Saudi Labor Law, related to your inquiry:
Article 84:
If the work relationship ends, the employer must pay the worker a reward for the period of his service, which is calculated on the basis of a half-month wage for each of the first five years, and a month’s wage for each of the following years, and the last wage is taken as a basis for calculating the reward. Parts of the year in proportion to what he spent at work.