1. The monthly principal is 20W (number of loan years).

Two. Calculation formula of equal principal and interest (monthly repayment amount) = [loan principal × monthly interest rate ×( 1 interest rate )× repayment months ]=[( 1 interest rate )× repayment months]

Three. Average fund calculation formula (monthly repayment amount) = (loan principal/repayment months) (principal-accumulated amount of repaid principal) × monthly interest rate.

Four. 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.

Extended data:

Average capital

The loan with equal principal and interest is calculated according to compound interest. 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.

The monthly repayment amount is unchanged, which is essentially that the proportion of principal increases month by month, the proportion of interest decreases month by month, and the number of monthly repayments remains unchanged, that is, in the distribution proportion of "principal and interest" for monthly payment, the proportion of interest paid in the first half of the year is large, and the proportion of principal is small. After more than half of the repayment period, it gradually turns into a large proportion of principal and a small proportion of interest.

The average capital loan uses a simple interest rate method to calculate interest. 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.

The monthly repayment amount decreases, showing a state of decreasing month by month; It divides the loan principal equally according to the total repayment months, plus the interest of the remaining principal in the previous period, thus forming the monthly repayment amount, so the repayment amount of the average capital method is the largest in the first month, and then decreases month by month, and the less the more.

Compared with the two, in the case of the same loan term, amount and interest rate, at the initial stage of repayment, the monthly repayment amount of average capital repayment method is greater than the equal principal and interest. However, according to the whole repayment period, average capital's repayment method will save the expenditure of loan interest.

The advantage of matching principal and interest is that the monthly repayment amount is the same, which is convenient for arranging income and expenditure. Suitable for borrowers whose economic conditions do not allow early repayment and excessive investment, and whose income is relatively stable. The disadvantage is that you need to pay more interest. However, most of the advance payment is interest, and the proportion of principal will increase after half of the repayment period, which is not suitable for early repayment.

The advantage of average capital is that the total interest is less than the equal principal and interest. The repayment amount decreases every month, and the later, the easier it is. Moreover, due to the large proportion of principal and small proportion of interest, it is very suitable for early repayment. The disadvantage is that the pressure of prepayment is great, and it needs to have a certain economic foundation and can withstand the pressure of prepayment.

Paying more principal and less interest in the early stage of average capital is obviously more suitable for early repayment.

In the monthly repayment of equal principal and interest in the previous period, the proportion of principal is small and the proportion of interest is large, which is not suitable for early repayment.

How to choose equal principal and interest and average capital?

The less the total loan (500,000-200,000), the shorter the service life (5- 10 year), and there is little difference between them. Generally, the total interest difference is within 0. 1- 1 ten thousand yuan.

The higher the total loan amount (more than 6,543.8+0,000) and the longer the service life (more than 654.38+0.5), there is a big gap between them, and the interest paid by equal principal and interest will exceed 6,543.8+0,000 yuan relative to the average capital.

Develop a repayment method that suits you and do what you can. If there is no intuitive understanding of the figures, you can use the mortgage calculator to calculate the difference between the equal principal and interest and the average capital in advance.