Understanding APR and Interest

## Understanding APR and Interest APR -- **Annual Percentage Rate** -- is the yearly cost of borrowing money on your credit card, expressed as a percentage. It is the single most important number to understand if you ever carry a balance. ### How APR Works Although APR is expressed as an annual rate, credit card interest is actually calculated **daily**. Here is how: 1. **Daily Periodic Rate (DPR):** Divide your APR by 365. For example, a 24% APR means a daily rate of about 0.0658%. 2. **Daily Interest Charge:** Multiply the DPR by your outstanding balance each day. 3. **Monthly Interest:** The daily charges are summed at the end of your billing cycle and added to your balance. **Example:** If you carry a $2,000 balance at 24% APR: - Daily rate: 24% / 365 = 0.0658% - Daily interest: $2,000 x 0.000658 = **$1.32 per day** - Monthly interest: roughly **$39.50** added to your balance That $2,000 purchase now costs you an extra $39.50 every month you do not pay it off. ### Variable vs. Fixed APR - **Variable APR:** Tied to an index rate, usually the U.S. Prime Rate. When the Federal Reserve raises or lowers rates, your APR moves with it. The vast majority of credit cards today have variable APRs. - **Fixed APR:** Stays the same regardless of market changes. These are rare for credit cards but common for some personal loans. Note that issuers can still change a "fixed" rate with 45 days' advance notice. ### Types of APR on Your Card Most credit cards have multiple APRs for different transaction types: - **Purchase APR:** Applies to everyday purchases. This is the rate most people refer to. - **Cash Advance APR:** Applies when you withdraw cash from an ATM using your credit card. This rate is almost always higher (often 25-30%) and has **no grace period** -- interest starts immediately. - **Balance Transfer APR:** Applies to balances moved from another card. Promotional offers may start at 0% for 12-21 months. - **Penalty APR:** A punitive rate (often 29.99%) triggered by paying late by more than 60 days. It can apply to your entire balance. ### The Grace Period: Your Best Friend The **grace period** is the time between the end of your billing cycle and your payment due date, typically **21 to 25 days**. During this window, no interest accrues on new purchases -- **but only if you paid your previous statement balance in full.** If you carry any balance from the prior month, the grace period disappears and interest begins accruing on new purchases immediately. This is one of the most important reasons to pay in full every month. ### Key Takeaways - APR is the annual cost of borrowing but is applied daily to your balance. - Most credit cards have variable APRs that change with the Prime Rate. - Cash advances carry higher APRs and no grace period -- avoid them. - Paying your full statement balance preserves your grace period and keeps interest at zero.