Ping An New Loan180,000, with three-year interest of 30,000, 4% and 6%. The interest is 30000 ÷ 36 = 833.33333, and one month's interest is 833 ÷180000 = 0.00000.5000080086 The loan interest is calculated by monthly compound interest, that is, after the end of each interest period, the remaining interest will be added to the principal to calculate the next period. In each interest-bearing period, the interest of the previous interest-bearing period will become the interest-bearing principal, that is, interest will be generated from interest, which is also commonly known as "rolling interest".