How are the interests of a credit card calculated?

Understanding how interest is calculated on a credit card will help you make important decisions about managing your personal finances.

Financial institutions offer several alternatives or credit card categories. Sure you know them. In Mexico there are internationally recognized franchises, such as MasterCard and Visa. There are Gold, Platinum, World, Classic, Premium, Bussiness cards, etc. In a country there are slightly more than 100 approved credit card products.

And each card has its benefits, its costs or commissions and its interests.


What does interest calculation depend on? Of the business you do

credit loan

Basically, there are three ways to finance purchases or dispose of cash with credit cards. That depends on the way in which interest is later settled.

  • Revolving or revolving credit: In this mode, each time you make a purchase or order cash, automatically, the total value will be divided by 36 parts. Each month, at least one part must be paid.
  • Monthly payment: In this mode, you can choose the number of fees to pay for the purchase or request for cash, from one to 36 (some up to 48) monthly payments. The payment will be fixed, the same, during all the time.
  • Cash payment: in this mode, the customer chooses to pay 100% of the purchase or advance in cash, in the next billing.


How the interests of a credit card are calculated

How the interests of a credit card are calculated

In the revolving or revolving system there are two types of interests:

  • The debtor or deferred interest: is the one that applies to the value of the operation from the date of purchase or effective request until the date of payment of the first installment.
  • The accrued or projected interest is generated on the minimum revolving capital (each of the 36 parts), caused between the time period of the previous settlement and the next payment date.

The sum of both interests will be integrated into the payment of the month. If you have performed several operations, they will add up all the interests of all purchases and cash requests.

The important thing to understand in this modality is that the business has automatically deferred in 36 minimum revolving amounts, generating two interest rates.

This system will imply that the monthly payments will be smaller than if you choose a period of six months, for example. But, of course, you will pay more in interest.


At monthly payments

credit payment

The interests in this system depend on the number of days the business will take. You will choose if you want to pay three months or twelve months.

The first period will always be the same as the days elapsed between the purchase and the settlement date. The others will be equal to the days between the last payment date and the settlement.

A purchase of $ 1,000 MX pesos for twelve months, can be seen as follows:

Figures in Mexican Pesos


Do not. Balance Capital subscription Interests Monthly payment
one 1000 65.29 49.01 114.3
two 934.71 68.49 45.81 114.3
3 866.22 64.05 50.25 114.3
4 802.17 74.99 39.31 114.3
5 727.18 74.74 39.56 114.3
6 652.44 77.63 36.67 114.3
7 574.81 85.1 29.2 114.3
8 489.71 87.66 26.64 114.3
9 402.05 92.43 21.87 114.3
10 309.62 98.01 16.29 114.3
eleven 211.61 103.17 11.13 114.3
12 108.44 108.44 5.86 114.3

The quota is always the same. What changes is the amortization or payment to the debt that is made each month? During the twelve months, of the total value paid, $ 114.30 MX pesos, more and more of it is devoted to the payment to capital (amortizing the debt) and less and less to interest.

The benefits of this modality? Be able to choose the number of fees to pay for the operation performed. Clearly, the smaller the period of time, the less interest will be paid.


Payment payment

Payment payment

This modality does not generate interest!

When you request that the charge be deferred to one month, 100% of the value will be paid without interest. It’s called the grace period.

Some financial entities, in special times, extend the grace period.

What is the grace of this system? Do not pay interest. It is a good way to take advantage of the convenience of paying with the credit card and adding points or miles.

Of course, the most important question is missing: At what rate will interest be paid? Each card has its Ordinary Monthly Interest Rate according to the category.

In your statement, you can see at what rate you are negotiating.