If you make $ 8,000,000 a year living in Taiwan, you will be taxed $ 2,675,933. That means that your net pay will be $ 5,324,067 per year, or $ 443,672 per month. Your average tax rate is 33.5% and your marginal tax rate is 59.4%. 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 $ 59.36, hence, your net pay will only increase by $ 40.64.
A $ 1,000 bonus will generate an extra $ 406 of net incomes. A $ 5,000 bonus will generate an extra $ 2,032 of net incomes.