How Is Credit Card Interest Calculated?


Credit card interest can be a mysterious aspect of owning a credit card, and it can be difficult to understand how much interest you’re actually paying on your balance. By learning how credit card interest is calculated, you can make better decisions about your spending and manage your credit card debt more effectively. It’s even possible to get credit card debt forgiven if you know where to look. In this article, we’ll walk you through the steps of calculating credit card interest so you can have a better grasp on this important aspect of personal finance.

Step 1: Understand Your Annual Percentage Rate (APR)

The first step to calculating credit card interest is understanding your card’s Annual Percentage Rate (APR). This is the interest rate your credit card issuer charges you for carrying a balance on your card. The APR is usually expressed as a yearly percentage, but it’s important to note that credit card interest is typically calculated on a daily basis. The APR can vary depending on the type of card you have, your credit score, and your payment history with the issuer.

Step 2: Determine Your Daily Periodic Rate (DPR)

To calculate credit card interest, you’ll first need to determine your Daily Periodic Rate (DPR). The DPR is the interest rate applied to your outstanding balance each day. To calculate the DPR, divide your card’s APR by 365 (the number of days in a year). This will give you a decimal, which represents the percentage of interest charged daily. For example, if your APR is 18%, your DPR would be 0.00049315 (0.18 ÷ 365).

Step 3: Calculate Your Average Daily Balance (ADB)

Next, you’ll need to find your Average Daily Balance (ADB). The ADB is the average balance you carried on your card during the billing period. To calculate this, add up your daily balances for the entire billing cycle and then divide by the number of days in the billing cycle. This will give you a single number that represents your average balance for the period.

For example, let’s say your billing cycle is 30 days long, and your daily balances for the month were as follows:

  • Day 1: $1,000
  • Day 2: $1,050
  • Day 3: $1,100
  • Day 30: $1,800

To calculate your ADB, add all the daily balances together and then divide by 30:

($1,000 + $1,050 + $1,100 + … + $1,800) ÷ 30 = $1,450

In this example, your ADB for the billing period would be $1,450.

Step 4: Calculate Your Interest Charges

Now that you have your DPR and ADB, you can calculate your interest charges for the billing period. To do this, multiply your ADB by your DPR, and then multiply that number by the number of days in the billing cycle. The result will be your interest charge for the period.

Using the previous example, with an ADB of $1,450 and a DPR of 0.00049315, your interest charge would be:

$1,450 x 0.00049315 x 30 = $21.46

So, for this billing cycle, you would be charged $21.46 in interest.

Conclusion: Understanding and Managing Your Credit Card Interest

Calculating credit card interest may seem daunting at first, but once you understand the steps involved, it becomes much easier to manage your credit card debt. By keeping track of your APR, DPR, and ADB, you can anticipate how much interest you will be charged on your balance and plan your payments accordingly. It’s important to remember that the longer you carry a balance on your credit card, the more interest you will accrue, so it’s always best to pay off your balance in full each month if possible. If you’re struggling with credit card debt, there are also resources available to help, such as credit counseling and debt consolidation programs. Overall, being informed and proactive about your credit card interest can help you make better financial decisions and ultimately achieve your personal finance goals.