Summary
If you make 128,179,992 LL a year living in Lebanon, you will be taxed 18,987,798 LL. That means that your net pay will be 109,192,194 LL per year, or 9,099,349 LL per month. Your average tax rate is 14.8% and your marginal tax rate is 21.0%. 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 21 LL, hence, your net pay will only increase by 79 LL.
Bonus Example
A 1,000 LL bonus will generate an extra 790 LL of net incomes. A 5,000 LL bonus will generate an extra 3,950 LL of net incomes.