When the current interest rate is 7%, interest = deposit amount *7%* deposit period. As the basic calculation method of bank deposit interest and loan interest. The interest calculation formula has played an important role in the daily settlement of banks and the daily life of ordinary people, and its role 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 1,000 yuan deposit will receive regular annual interest in 90 yuan, and the monthly interest rate of 6% is written as 6‰, that is, the monthly interest rate of every 1,000 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 1,000 yuan deposit is1.

In order to calculate interest conveniently, 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 the cents below yuan do not pay interest; 2. The interest amount shall be calculated to one decimal place and rounded off when actually paid; 3. Except for the annual settlement of current savings, the interest can be transferred to the principal. Regardless of the deposit term, 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 head counting method instead of the tail counting method; 2. Every month is calculated as 30 days, regardless of big month, small month, flat month and leap month, and every year is calculated as 360 days. 3. The maturity date of all kinds of deposits shall be calculated on an annual basis and on a monthly basis. If the account opening date is the missing date of the due month, the last day of the due month will be the due date. After understanding the calculation method of interest, you can calculate the corresponding interest by looking at which bank you choose and the interest given by the bank you choose.