PHOTO: iStock

CNN Underscored reviews financial products such as credit cards and bank accounts based on their overall value. We may receive a commission through The Points Guy affiliate network if you apply and are approved for a card, but our reporting is always independent and objective.

Before detailing our methodology for ranking credit cards, we have to acknowledge an awkward reality: There isn’t a “best” credit card. That’s because the best credit card is the one that matches your personal priorities, whether it be earning cash back, utilizing robust travel perks, relying on the security of purchase protections, redeeming rewards for over-the-top travel, avoiding fees, or one of many other credit card features. To put it another way, the “best credit card” is in the eye of the beholder.

That said, here at CNN Underscored, we stay on top of the rapidly changing landscape of credit card offers, so you can be sure you’re always getting the best options for the credit card perks and benefits that matter to you. Here’s what you need to know about how CNN Underscored reviews credit cards and how you can find the credit card that’s right for you.

Our three basic rules of credit cards

Before we dive into our extensive criteria, let’s briefly review CNN Underscored’s three key rules to keep in mind when it comes to credit cards:

1) Avoid interest by always paying your balance in full and on time.

Credit cards today offer rich rewards and exciting benefits, but the moment you start paying interest, you’ve lost the game. Banks are only able to provide extensive credit card perks because they know a certain percentage of their users will end up paying exorbitant interest that more than covers the cost of those perks. You don’t want to be one of those people.

That’s why it’s vital to be sure you never carry a balance on your credit card. Successful use of credit cards means substituting them for cash or a debit card as a payment method, not using them to live beyond your means. Only use a credit card to buy things you were planning to buy anyway.

And if you don’t feel you can be disciplined enough to do that, or you’re already deep in credit card debt, you may want to avoid getting a new credit card entirely unless it’s for the specific purpose of reducing the interest you’re paying on existing debt through an introductory balance transfer offer.

2) Choose a credit card that fits your personal needs.

Your friends might gush about an exciting new credit card that offers free airport lounge access, but if you only fly once or twice a year, how much will you personally be able to use that benefit?

There are hundreds of credit cards on the market with dozens of different features, so you want to pick a card whose features most closely match your needs and spending habits, not just one that happens to be popular at the moment. When choosing a credit card, think about the types of places where you spend money every day or every week.

For instance, if you prefer cooking at home to eating out, you’ll likely want a credit card that offers bonus cash back or points on groceries, not one that gives extra rewards at restaurants.

3) Yesterday’s credit card may not be the right card for you today.

The credit card market is incredibly dynamic, with new cards introduced and old cards revamped regularly, so you can’t just pick a card and assume it’ll be a good choice for the next decade. Even if you applied for a credit card only a few years ago, it’s likely there’s a new or improved card that’s now a better choice.

Also, your own needs or spending habits may have changed over time — perhaps you used to travel regularly for work, but now you’ve been promoted to a job that keeps you at home more often. That’s why, when it comes to CNN Underscored’s credit card reviews and guides, we extrapolate both the costs and the value of the card’s benefits over a period of only three years, so that both one-time and recurring benefits average out over time.

Other sites use longer periods for their analysis, but we don’t believe you should wait longer than three years before you consider changing credit cards.

Our credit card criteria

PHOTO: iStock

How do we determine which credit cards are worth considering? Here are the criteria we use:

Earning rate: How much in cash back or points and miles does the card earn on purchases? This can get complex when it comes to bonus categories and earning caps, so we use the federal Bureau of Labor Statistics’ data on average household spending in various categories as a basis for how much the typical household could potentially earn with the card in a year.

Redemption value: Not all points and miles are worth the same amount — how much value can you get for rewards earned with the card? Cash back cards are easy to compare, but when it comes to travel rewards, we use the points valuations from our partner The Points Guy — which covers all the major airline, hotel and bank points and miles — as part of our calculations to determine the redemption return on each credit card and create an apples-to-apples comparison for cash back credit cards.

Ease of redemption: How complicated is it to use your rewards? If it’s a cash back card, can you apply the money you’ve earned directly to your credit card balance with no minimums? If it’s a transferable travel rewards card, how robust is the partner list? Does it have any US airline programs as partners? And how quickly do the points transfer?

Interest rate: At CNN Underscored, we don’t recommend ever paying credit card interest. That’s because even the lowest credit card interest rate will cost you much more than the rewards you’re earning with the card or travel perks you’re using. However, there are rare times when financing a large purchase is necessary and a low introductory interest rate on purchases can be useful.

Balance transfer offer: Speaking of interest, if you’re already underwater in credit card debt, a credit card with a low-interest balance transfer offer can serve as the first step in digging your way out of debt. It’s a feature that’s generally only useful for people who already owe money, but for folks who need it, it can be a lifesaver. We consider cards based on both the interest rate and the length of the introductory offer, as well as any fee charged for using the balance transfer option.

Fees: We’re not saying you should never pay annual fees, but if you are, you’d better be getting at least enough in value from the card to offset whatever it’s costing you to keep the card every year. For instance, a card with a $95 annual fee requires $4,750 in spending at 2% cash back each year just to break even. And some cards feature fees beyond an annual fee, such as foreign transaction fees when you use the card for overseas purchases, or balance transfer fees when you transfer debt from another credit card to that one.

Travel protections: When you’re traveling, stuff happens. Some cards will reimburse you when you suffer a trip delay or interruption, or have your checked bags delayed or lost, or even if you have to cancel your trip. You’ll sometimes find features you can also use when you’re closer to home, such as roadside assistance or collision damage coverage when you rent a car.

Purchase protections: They’re not as common as they used to be, but some cards still offer additional insurance coverage on purchases you make, whether it’s by extending the manufacturer’s warranty, rebating your cost if the price drops on an item shortly after you bought it, or refunding your money for recent purchases that get damaged or stolen. Cell phone insurance is also becoming an increasingly popular credit card feature.