Summary
If you make 40,300,000 LL a year living in Lebanon, you will be taxed 4,266,000 LL. That means that your net pay will be 36,034,000 LL per year, or 3,002,833 LL per month. Your average tax rate is 10.6% and your marginal tax rate is 12.0%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 LL in your salary will be taxed 12 LL, hence, your net pay will only increase by 88 LL.
Bonus Example
A 1,000 LL bonus will generate an extra 880 LL of net incomes. A 5,000 LL bonus will generate an extra 4,400 LL of net incomes.