How Is Daily Interest Calculated on A Credit Card

Credit card daily interest is calculated based on the average daily balance and the card's annual percentage rate (APR). This interest is typically compounded daily, meaning it's calculated and added to your balance each day. Understanding how this works can help you manage your credit card debt more effectively.

How Daily Interest Works

When you carry a balance on your credit card, the issuer calculates interest daily based on your average daily balance and the card's APR. Here's how it typically works:

The card issuer calculates your average daily balance for each billing cycle.
They apply the daily interest rate (APR divided by 365) to this average balance.
This daily interest is added to your balance, and the process repeats each day.
At the end of the billing cycle, the total interest is added to your statement.

Daily interest calculations can vary slightly between card issuers, but the basic principle remains the same.

Calculation Formula

The daily interest calculation typically follows this formula:

Daily Interest = (Average Daily Balance × Daily Interest Rate) / 100

Where:

Average Daily Balance - Your average balance for the day
Daily Interest Rate - Your card's APR divided by 365

For example, if your APR is 20% (0.20), the daily interest rate would be 0.20/365 ≈ 0.0005479.

Example Calculation

Let's say you have a $1,000 balance on your credit card with a 20% APR. Here's how the daily interest would be calculated:

Daily interest rate = 20% ÷ 365 ≈ 0.05479%
Daily interest = $1,000 × 0.0005479 ≈ $0.55
After 30 days, total interest ≈ $0.55 × 30 ≈ $16.50

This means your balance would grow by approximately $16.50 in interest charges over 30 days.

How to Use This Calculator

Use the calculator in the sidebar to estimate your daily interest charges. Simply enter your:

Current balance
Card's APR
Number of days

The calculator will show you the estimated daily interest and total interest for the period.

FAQ

How often is daily interest calculated?: Daily interest is typically calculated and added to your balance each day, based on your average daily balance.
Does daily interest compound?: Yes, daily interest typically compounds, meaning each day's interest is calculated on the previous day's balance plus any interest already accrued.
How does the grace period affect daily interest?: If you pay your balance in full within the grace period (usually 21-25 days), you won't be charged interest for that billing cycle.
Can I avoid daily interest charges?: Yes, by paying your balance in full each month before the grace period ends, you can avoid interest charges.
What if I make partial payments?: Partial payments may still result in interest charges, as the issuer may calculate interest based on your average daily balance.