If you make RM 1,200,000 a year living in Malaysia, you will be taxed RM 426,175. That means that your net pay will be RM 773,825 per year, or RM 64,485 per month. Your average tax rate is 35.5% and your marginal tax rate is 38.7%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of RM 100 in your salary will be taxed RM 38.68, hence, your net pay will only increase by RM 61.32.
A RM 1,000 bonus will generate an extra RM 613 of net incomes. A RM 5,000 bonus will generate an extra RM 3,066 of net incomes.