For example, if an investor invests the 5000 yuan (a) saved in the first year, he will get a return of 3% every year (i), and then he will invest the sum of these principal and interest together with the 5000 yuan he needs to pay every year in a new round of investment.

Then after 30 years (n), his total assets will become: f = 5000× [(1+3%)-1]/3% = 237877.08. Among them, investors invested a total of 5000X30= 150000 yuan, and earned a total interest of 87877.08 yuan.

Extended data

f = p×（ 1+I）？

f = A（（ 1+I）？ - 1）/I

p = F/（ 1+I）？

p = A（（ 1+I）？ - 1）/（I（ 1+I）？ )

a = Fi/（（ 1+I）？ - 1)

a = P（I（ 1+I）？ ）/（（ 1+I）？ - 1)

F: future value, or future value, that is, the sum of principal and interest at the end of the period; P: present value, or initial amount; A: Annuity, or equivalent; I: interest rate or discount rate; N: Number of interest-bearing periods.

The characteristics of compound interest calculation: the sum of the principal and interest at the end of the previous period is taken as the next principal, and the amount of each principal is different when calculating.

Baidu encyclopedia-compound interest calculation formula

Baidu encyclopedia-compound interest