Summary
If you make 644,800,000 ₫ a year living in Vietnam, you will be taxed 172,999,827 ₫. That means that your net pay will be 471,800,173 ₫ per year, or 39,316,681 ₫ per month. Your average tax rate is 26.8% and your marginal tax rate is 33.1%. 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 33.06 ₫, hence, your net pay will only increase by 66.94 ₫.
Bonus Example
A 1,000 ₫ bonus will generate an extra 669 ₫ of net incomes. A 5,000 ₫ bonus will generate an extra 3,347 ₫ of net incomes.