Summary
If you make 55,640,000 ₫ a year living in Vietnam, you will be taxed 8,350,144 ₫. That means that your net pay will be 47,289,856 ₫ per year, or 3,940,821 ₫ per month. Your average tax rate is 15.0% and your marginal tax rate is 16.3%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of 100 ₫ in your salary will be taxed 16.29 ₫, hence, your net pay will only increase by 83.71 ₫.
Bonus Example
A 1,000 ₫ bonus will generate an extra 837 ₫ of net incomes. A 5,000 ₫ bonus will generate an extra 4,186 ₫ of net incomes.