A: Monthly payment;

F: total loan amount;

I: loan interest rate (monthly interest rate);

N: repayment months

: motivation.

The calculation method of interest and principal is: first calculate the monthly repayment amount according to the above formula, and then calculate the monthly interest and principal according to the repayment time.

For example, the loan is 500,000 yuan, the time is 20 years, the interest rate is 5.9%, and the monthly repayment amount is 3,553.37 yuan.

First month: interest = 500,000× 5.9%/12 = 2,458.33 yuan, principal = 3,553.37-2,458.33 =1095.04 yuan;

Second month: interest = (500000-1095.04) × 5.9%/12 = 2452.95 yuan, principal = 3553.37-2452.95 =100.

The third month: interest (500000-1095.04-1100.42) × 5.9%/12 = 2447.54, and principal = 3557.37-2447.54. ......

Matching loans are divided into equal principal and interest loans and average capital loans. Compared with ordinary capital loans, ordinary capital loans can save a lot of interest under normal repayment conditions.

1. Matching principal and interest loan: compound interest is adopted. At the settlement time of each repayment, the interest generated by the remaining principal will be calculated together with the remaining principal (loan balance), that is to say, the outstanding interest will also be calculated, which seems to be more severe than "rolling interest". In foreign countries, it is recognized as a loan method suitable for the interests of lenders.

2. Average capital loan: interest is calculated by simple interest rate method. At the settlement time of each repayment, only the remaining principal (loan balance) is calculated, that is to say, the outstanding loan interest is not calculated together with the outstanding loan balance, only the principal is calculated.

3. Therefore, under the traditional repayment method, the longer the loan cycle, the more interest the loan with equal principal and interest will generate than the loan with average capital. Therefore, if the borrower cannot adjust (or choose) the repayment method, the borrower with longer loan term should choose the average capital loan.