If you make HK$400,000 a year living in Hong Kong, you will be taxed HK$42,500. That means that your net pay will be HK$357,500 per year, or HK$29,792 per month. Your average tax rate is 10.6% and your marginal tax rate is 17.0%. This marginal tax rate means that your immediate additional income will be taxed at this rate. For instance, an increase of HK$100 in your salary will be taxed HK$17, hence, your net pay will only increase by HK$83.
A HK$1,000 bonus will generate an extra HK$830 of net incomes. A HK$5,000 bonus will generate an extra HK$4,150 of net incomes.
NOTE* Withholding is calculated based on the tables of Hong Kong, income tax. For simplification purposes some variables (such as marital status and others) have been assumed. This document does not represent legal authority and shall be used for approximation purposes only.