Interest = principal * interest rate * number of interest-bearing periods

I = P * i * n

Interest rate (I) usually gives the annual interest rate and monthly interest rate, and the daily interest rate should be converted.

Monthly interest rate = annual interest rate/12 (month)

Daily interest rate = annual interest rate /360 (days) = monthly interest rate /30 (days)

∴ Interest =10000× 0.097 %× 360×1= 3492 yuan.

The interest of 3492 yuan a year is 3492/ 12=29 1 yuan a month.

For example, if you borrow 50,000 yuan and pay it back in one year, the daily interest rate is 0.05%, so what is the total interest for one day?

Total interest = 50,000× 360× 0.05% = 9,000 yuan. This is only a rough estimate. If compound interest was calculated last month:

The first month: 50,000× (30× 5/10000) = 750 yuan.

Second month: (50,000+750) × (30× 5/10000) = 761.25 yuan.

By analogy, you can calculate the monthly interest, and add up all the interest in this year, so the actual annual interest is about 9 100, and the annual interest rate reaches 18%.

Baidu encyclopedia-interest