Summary
If you make 321,100,000د.ت a year living in Tunisia, you will be taxed 132,561,274د.ت. That means that your net pay will be 188,538,726د.ت per year, or 15,711,561د.ت per month. Your average tax rate is 41.3% and your marginal tax rate is 41.3%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100د.ت in your salary will be taxed 41.28د.ت, hence, your net pay will only increase by 58.72د.ت.
Bonus Example
A 1,000د.ت bonus will generate an extra 587د.ت of net incomes. A 5,000د.ت bonus will generate an extra 2,936د.ت of net incomes.