As the basic calculation method of bank deposit interest and loan interest. The interest calculation formula has played a great role in the daily settlement of banks and the daily life of ordinary people, and it will become more and more important. The interest rate of savings deposits shall be stipulated by the state and promulgated by the People's Bank of China. Interest rate, also known as interest rate, is the ratio of interest to principal on a certain date, which is generally divided into annual interest rate, monthly interest rate and daily interest rate.
The annual interest rate is expressed as a percentage, the monthly interest rate is expressed as one thousandth and the daily interest rate is expressed as one thousandth. If the annual interest rate of 9% is written as 9%, that is to say, every thousand yuan deposit will get the regular annual interest rate in 90 yuan, and the monthly interest rate of 6% is written as 6‰, that is, the monthly interest rate of every thousand yuan deposit is written as 6 yuan, and the daily interest rate of 1% 5 cents is written as 0. 15‰, that is, the daily interest rate of every thousand yuan deposit is 1.5 cents.
In order to facilitate interest calculation, three kinds of interest rates can be converted, and the conversion formula is: annual interest rate ÷ 12= monthly interest rate; Monthly interest rate ÷30= daily interest rate; Annual interest rate ÷360= daily interest rate.
In addition, we need to know the starting point of the interest calculation formula: 1, and the starting point of interest for savings deposits is yuan, and no interest is paid for points below yuan; 2. The interest amount shall be calculated to one decimal place and rounded to one decimal place when actually paid; 3. Except that the current savings are settled on an annual basis and the interest can be converted into principal, regardless of the deposit period, the interest of other savings deposits will be paid off with the principal at the time of withdrawal, excluding compound interest.
The calculation of deposit period in the interest calculation formula is 1, and the calculation of deposit period adopts the method of counting head instead of tail; 2. Every month is counted as 30 days, regardless of big month, small month, flat month and leap month, and every year is counted as 360 days. 3. The maturity date of all kinds of deposits shall be calculated annually and monthly. If the account opening date is the missing date of the due month, the last day of the due month is the due date. After understanding the calculation method of interest, look at which bank you choose and then look at the interest given by the bank you choose, and you can calculate the corresponding interest.
Relationship between annual interest rate and monthly interest rate: monthly interest rate = annual interest rate/12, annual interest rate = monthly interest rate * 12. For example, the annual interest rate is 7.05%, which translates into a monthly interest rate of 7.05%/ 12=5.875‰ (generally, the interest rates of banks in mortgage contracts are expressed by monthly interest rates).
The monthly interest announced by the bank is basically expressed after one year. For example, the annualized deposit interest rate for three months is 2.6% (the bank is listed), but the actual rate of return for the current period is only 0.65%, the annual interest rate is generally% (percentage), and the monthly interest rate is generally expressed as ‰ (one thousandth); The daily interest rate is expressed as a few tenths of the principal, which is usually called a few cents. If the daily interest rate is 1%, that is, the principal is 1 yuan, and the daily interest rate is 0.005438+0 yuan. (1% =0.00 1 yuan, 10 cents =0.000 1 yuan)
Calculation formula: daily interest rate _ annual interest rate ÷360= monthly interest rate ÷30