How Daily Interest Is Calculated on Credit Card Balance
'/%3E%3Ccircle cx='48' cy='39' r='19' fill='%23f2c9a5'/%3E%3Cpath d='M27 35c3-16 39-17 42 2-8-8-27-9-42-2z' fill='%23374151'/%3E%3Cpath d='M21 86c5-24 49-28 56 0z' fill='%232563eb'/%3E%3Ccircle cx='41' cy='41' r='2' fill='%23111827'/%3E%3Ccircle cx='55' cy='41' r='2' fill='%23111827'/%3E%3Cpath d='M42 52c4 3 9 3 13 0' stroke='%2392400e' stroke-width='3' fill='none' stroke-linecap='round'/%3E%3C/svg%3E)
Reviewed by Calculator Editorial Team
Credit card daily interest is calculated based on your outstanding balance and the card's annual percentage rate (APR). This guide explains how the calculation works, what factors affect it, and how to estimate your daily charges.
How Daily Interest Works
Most credit cards charge interest on a daily basis, meaning your balance grows with compounding interest every day. This is different from monthly interest, which is calculated once per billing cycle.
Daily interest calculations are typically based on the average daily balance during the previous day. This means your interest charges can vary significantly depending on when you make payments and how your balance changes throughout the month.
Note: Some credit cards use a different method called "average daily balance" (ADB) or "average daily balance reporting" (ADBR), which can affect how interest is calculated.
Calculation Method
The basic formula for calculating daily interest is:
Where:
- Daily Balance - Your average balance for the day
- Daily Interest Rate - Your card's APR divided by 365
- 365 - The number of days in a year (or 366 for leap years)
For example, if your card has a 20% APR, the daily interest rate would be 20% ÷ 365 ≈ 0.0548% per day.
Factors Affecting Daily Interest
Several factors influence how much daily interest you'll accrue:
- APR - Higher APRs result in more daily interest charges
- Balance - Larger balances generate more interest
- Payment Timing - Paying at the end of the month minimizes interest
- Grace Period - Some cards offer a grace period with no interest
- Minimum Payments - Making only the minimum payment can lead to higher interest
The table below shows how different balances and APRs affect daily interest:
| Balance | APR | Daily Interest |
|---|---|---|
| $1,000 | 15% | $0.41 |
| $2,000 | 20% | $1.09 |
| $3,000 | 25% | $2.06 |
Example Calculation
Let's calculate the daily interest for a $1,500 balance with a 18% APR:
- Convert APR to daily rate: 18% ÷ 365 ≈ 0.0493% per day
- Calculate daily interest: $1,500 × 0.000493 ≈ $0.74
Over 30 days, this would accumulate to approximately $22.20 in interest.
Remember: This is a simplified example. Actual interest may vary based on your card's specific terms and when payments are made.