4.45% bank loan interest rate means 4 points, 4 points and 5 points. Take 1 10,000 principal as an example, and the interest is 445 yuan. 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, ten cents =0.000 1 yuan) Then 4.45%=0.0445, which is 4 minutes and 4 centimeters. According to the formula, interest = principal * interest rate. Taking 1 ten thousand yuan of principal as an example, the following formula can be obtained: annual interest = 65438.