How to Calculate Your Credit Card Interest Rate

Table of Contents

An individual can use a credit card to make purchases later and pay for them at a later date. Every month, the credit card company issues a statement showing the balance, the minimum payment, the credit card interest, and the current due date. Interest is not charged if the customer repays the outstanding amount by its due date. Thus, every time she does not pay the card bill or carries the balance to the next payment cycle, she will be charged a credit card interest rate.

What determines the interest rate on credit cards?

A single purchase APR can be applied to some credit cards. Some have a range of rates – 13% to 23% – and your credit card interest rate will vary based on your credit score. A lower rate means you have better credit. A bank’s prime rate, which is the rate it charges its biggest customers, is linked to the rates and ranges it offers. It is common for credit card rates to rise with increases in prime rates. Different credit cards have different APRs. A credit card with rewards typically has a higher interest rate, and how can we get a credit card.

Factors determining interest rates:

Rates of interest currently prevailing 

Credit card rates are determined by these rates, also known as prime rates. Cardholders pay an estimated interest per month based on small changes in the prime rate.

An evaluation of the card issuer’s risk based on the user’s credit history 

Companies that offer credit cards consider your credit history and your credit score when determining your interest rate. Good credit scores mean low-interest rates and the reverse is also true.

Rates are different 

APR (annual percentage rate) is a common way to calculate interest, but a single credit card may have several APRs. It is possible to have different APRs when purchasing, making cash advances, transferring balances, and utilizing promotional rates. Depending on the card, APRs may change every six months or every year. A few cards offer fixed APRs, but most have variable rates.

Promotional offers 

Many credit cards offer various interest offers, usually for more than one year. Interest rates rise when the promotional period ends.

Payment history

In the event you fail to pay your card bill on time or pay only late fees, your interest rate will rise, sometimes dramatically.

Calculate the credit card interest rate

It takes three steps to calculate credit card interest. You can view the video above to see how that process works in detail, but here is a basic overview. Here is a copy of your credit card statement if you want to follow along. Here are some details you’ll need.

Calculate daily rate by converting annual rate

Your statement indicates your interest rate as your annual percentage rate or APR. Due to the daily basis on which interest is calculated, you must convert the APR into a daily rate. For our purposes, dividing by 360 makes no difference since it only alters the outcome by a hair. Hence, the term periodic interest rate, or sometimes the term daily periodic rate, is used.

You can determine your average daily balance by:

Upon receiving your statement, you will receive a breakdown of the billing period. Interest will be charged based on your balance for that particular period. Initially, the unpaid balance from the previous month is added to your new balance. When you purchase something, your balance goes up; it goes down when you pay it back. 

Write the daily balance for each day of the billing period using the transaction information on your statement. After that is done, figure out how many days in the billing period are by adding up all the daily balances. This gives you an average daily balance.