Calculation formula of mortgage interest rate

For those who buy a house by loan, the loan bank will generally give the annual interest rate of the loan, then provide two repayment methods, namely average principal or equal principal and interest, to choose from, and finally directly tell the results of monthly mortgage repayment, but this is not enough for friends who like to get to the bottom of it, because there is no calculation process, and they always feel that something is missing. Then, let's start with the calculation formula of mortgage interest rate and see what the specific calculation process is.

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I. Calculation formula of mortgage interest rate

1, average capital

Total interest = (number of installments+1)× total loan × monthly interest rate ÷2,

Monthly payment for each installment = monthly principal payable+monthly interest payable,

Monthly repayable principal = total loan amount, number of installments,

Monthly interest payable = [total loan-monthly principal payable * (current period-1)]* monthly interest rate,

Monthly interest rate = annual interest rate12 months.

2. Equal principal and interest

Total interest = number of installments * monthly repayment amount of each installment-loan principal,

Monthly repayment amount of each installment = [total loan × monthly interest rate ×( 1+ monthly interest rate) installments ]=[( 1+ monthly interest rate) installments-1],

Where ""stands for power, which is an operation mode in mathematics. For example, 2 12 means that the number 2 needs to be multiplied by 12 times repeatedly. You can do it yourself with a calculator and other tools.

Secondly, an example is given to illustrate the calculation process.

Assuming that the total loan amount is 240,000, the loan term is 20 years, that is, the loan will be repaid in 240 installments, with the annual interest rate of 4.8%, and the principal will be repaid in equal amount, then:

1, monthly interest rate = 4.8%12 months =0.4%,

2. Monthly payable principal = 240,000 ÷ 240 =11,000 yuan,

3. Total interest = (240+1) * 240000 * 0.4% ÷ 2 =115680 yuan,

4. The first month =1000+(240000-1000 * 0) * 0.4% =1960 yuan,

5. The second monthly payment =1000+(240000-1000 *1) * 0.4% =1956 yuan,

6. The third monthly payment =1000+(240000-1000 * 2) * 0.4% =1952 yuan,

Applying the formula in turn, we can see that the interest is decreasing according to the law of 4 yuan/month, and the monthly payment is decreasing according to the law of 4 yuan/month, because the principal payable remains unchanged.

The above is about the "mortgage interest rate calculation formula" related content, I hope to help you.