The calculation of credit card compound interest is to calculate the interest after adding up the principal and interest. Generally, the interest charged on credit cards is divided into cash withdrawal interest and overdue interest, and is generally charged at a daily interest rate of 0.5%. Compound interest is calculated monthly from the transaction date plus the principal and interest until the repayment date.

Compound Interest refers to an interest calculation method in which the interest for a certain interest calculation period is calculated by adding the principal plus the total interest accumulated in previous periods when calculating interest, which is commonly referred to as "Profits talk about profits" and "profits compound profits".

The characteristic of compound interest calculation is that the sum of principal and interest at the end of the previous period is used as the principal of the next period. The amount of principal in each period is different during calculation. The present value of compound interest refers to the principal that must be invested today to reach a specific amount of funds in the future when compound interest is calculated. The so-called compound interest, also known as interest plus interest, refers to the method of making a new round of investment with interest after a deposit or investment has received a return.

The compound interest future value refers to the sum of the principal after the principal earns interest within the agreed period, the interest is added to the principal and then the interest is calculated, and the period is rolled over to the end of the agreed period. Simply put, it means depositing A at the beginning of the period, taking i as the interest rate, and depositing the sum of principal and interest after n periods. Formula: F=A*(1+i)^n. Since inflation rate and interest rate are closely related, like two sides of the same coin, the formula for calculating the future value of compound interest can also be used to calculate the actual value of a specific fund in different years. Simply replace the interest rate in the formula with the inflation rate.

The future value of an ordinary annuity: refers to the sum of principal and interest of equal amounts of income or expenditure at the end of each period within a certain period, that is, the amount of each period is converted to the future value at the end of the last period based on compound interest, and then The total is the future value of the annuity. If the annuity has a large number of periods, it is obviously quite cumbersome to calculate the future value using the above method. Since the annual payments are equal and the coefficients for converting the future value are regular, a simple calculation method can be found. The significance of compound interest is that the benefits obtained can continue to generate benefits. The core of compound interest is to add the interest calculated on the principal of the previous period to the principal of the subsequent interest calculation, resulting in the interest obtained by the parties involved in compound interest becoming larger and larger. thus generating huge profits.