本文摘自某银行官网，用于解释不同种类APR之间的区别
What is APR?
You may have seen the term APR, or annual percentage rate, used in reference to everything from mortgages and auto loans to credit cards. In this piece, we look at credit card APRs—which you’ve probably seen listed on your monthly statements. Knowing what an APR is, how it’s calculated and how it’s applied can help you make more informed credit card decisions.
Understanding APR
Technically speaking, APR (annual percentage rate) is a numeric representation of your interest rate. When deciding between credit cards, APR can help you compare how expensive a transaction will be on each one. It’s helpful to consider two main things about how APR works: how it’s applied and how it’s calculated.
How does APR work
Generally, credit card companies offer a grace period for new purchases. If you only make purchases and pay off your ending balance each month by the due date, you pay just the amount you owe with no interest. However, if you opt to carry a balance on your card, you pay the agreed-upon interest on your outstanding balance.
How to calculate APR
Many variable interest rates start by using an index, such as the U.S. Prime Rate, and then add a margin. The result is the APR. Variable rates can change if the index changes, and some banks offer a non-variable APR as well. Here’s an example of how the rate is set:
The U.S. Prime Rate, as published in the Wall Street Journal
The margin the bank charges
Annual percentage rate
Figuring out what you owe
Banks use a formula to determine how much interest you pay on your outstanding balance. They calculate it using a daily or monthly periodic rate, depending on the card.
Keep in mind some accounts have multiple APRs, so this calculation may be applied for each one. The statement gives you more information about how to calculate the balance subject to interest rate.
Annual percentage rate
Days in a year
Daily periodic rate
DPR multiplied by days in billing period
Balance subject to interest rate
Interest charged
Types of APR
There are different APRs based on how you use your credit card. When you’re selecting a credit card, it’s a good idea to consider these rates in addition to your credit needs.
Purchase APR
The rate applied to credit card purchases.
Cash advance APR
The cost of borrowing cash from your credit card tends to be higher. There may be a different APR for checks or certain types of cash advances.
No grace periods.
Penalty APR
Usually the highest APR. It may also be applied to certain balances when you violate the card terms and conditions like failing to make payments on time.
Introductory APR
(or promotional APR) Features a lower APR for limited time period. It can apply to specific transactions as well as balance transfers, cash advances or any combination.
APR and the cardholder
Before you get any credit card, keep in mind:
- The APR can help you evaluate all offers and promotions.
- Generally, lenders cannot change the APR for the first 12 months. However, an APR can change in that period if it’s a promotional or variable rate or if the terms and conditions are violated.
- Consumers should review terms and conditions, including the APR, before using their cards.
- In most circumstances, when changing terms and conditions, companies must give 45 days advance notice.