Calculated based on the RMB exchange rate on that day. According to information from the official website of the Ministry of Finance of Hong Kong, China, the exchange rate for credit card payments is calculated based on the RMB exchange rate on that day. The consumption amount is converted into Hong Kong dollars, and then the Hong Kong dollars are converted into RMB according to the exchange rate. The final settlement amount is the amount you need to pay. Exchange rate refers to the exchange rate between two currencies. It can also be regarded as the value of one country's currency to another currency.