Details

Chinese income tax law mandates a deduction up front from an individual's income. If one is a non-Chinese citizen, the deduction is CNY 4800. If one is a Chinese national, the deduction is CNY 2000. Using the net amount, one needs to find the appropriate tax rate from a given table. Multiply the net amount and the appropriate tax rate; then deduct an amount that is predetermined by the Chinese government. Hence, there is always some sort of confusion about how much tax an expat needs to pay. (In the program, r[x] is the rate and d[x] is the deduction.)

For details, see http://www.chinatax.gov.cn.