Summary
If you make 4,112,709,120 KWD a year living in Kuwait, you will be taxed 3,255 KWD. That means that your net pay will be 4,112,705,865 KWD per year, or 342,725,489 KWD per month. Your average tax rate is 7.9% and your marginal tax rate is 0.0%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 KWD in your salary will be taxed 0 KWD, hence, your net pay will only increase by 100 KWD.
Bonus Example
A 1,000 KWD bonus will generate an extra 1,000 KWD of net incomes. A 5,000 KWD bonus will generate an extra 5,000 KWD of net incomes.