There is no magic number when it comes to credit card interest rates. It depends on a number of factors -- mostly, your credit score.

Image Credit: Getty Images

To give you a sense of the variance, the national average APR is 16.92% as of September 2018. However, the average interest rate on credit card accounts that are actually being charged interest is 15.54%. Low interest credit cards have a lower average of 13.99%, while cash-back credit cards average out at a much higher 17.09%. The average interest rate for credit cards from credit unions is only 9.37%. Finally, credit cards for people with bad credit top the list at an average APR of 24.18%.

The point is that a good credit card interest rate might not be the same for you as it is for your neighbor. If you’re more concerned with rewards and have no plans to carry a balance, a 17% APR isn’t that terrible. On the other hand, if you’re paying off credit card debt, a 17% APR is pretty high.

You should always aim for the lowest interest rate available to you, but the best interest rate you can get will depend on your credit score. Here are some guidelines to help you figure out what interest rate you should aim for based on your credit.

Good credit card interest rates for people with fair or bad credit

FICO® Score below 670

If you have fair or bad credit, you’re probably going to be looking at secured credit cards and credit cards for people with bad credit. While these are worthwhile for credit-building purposes, they do come with sky-high interest rates. These credit cards tend to have interest rates that start in the low 20s, so anything below 25% is not bad.

If you have no or very little credit, you could consider getting a student credit card. These are credit cards that are designed for students without much credit history, although you will need a source of income to qualify. These come with interest rates as low as 14.74%, although with no credit, your APR will probably be closer to 20%.

Finally, consider getting a credit card with your local credit union. Building a relationship with them through a checking account or getting a co-signer will help your chances of approval, and this could get you an interest rate in the 10% to 15% range.

Good credit card interest rates for people with good credit

FICO® Score of 670 to 739

If you have good credit, you don’t have to rely on secured credit cards with high APRs anymore. This means you can start looking at low interest credit cards, which offer interest rates as low as 11.74% if your credit score is high enough. Anything below 15% is not bad for a major credit card issuer, but the lower, the better.

Another option is to go for credit cards with 0% intro APR offers. These offers give you a 0% interest rate for a limited period of time, and that APR can apply to new purchases, balance transfers, or both. This is a good way to try out a new credit card without the risk of getting hit with interest fees or do a balance transfer to pay off existing debt interest free. Just make sure you pay off the balance in full before the promotional period ends.

Good credit card interest rates for people with excellent credit

FICO® Score of 740 or above

If you have very good or excellent credit, the sky’s the limit when it comes to credit cards. With a FICO® Score of 740 or above, you can generally qualify for all the best interest rates. This includes the low interest rate credit cards mentioned above, and you’re likely to get an APR on the low end of the specified range.

However, if you don’t plan to ever carry a balance (which is wise), and you have excellent credit, interest rate might not be the credit card feature to pay most attention to. With a high credit score, you can qualify for the best rewards credit cards on the market, including credit cards with huge sign-up bonuses and premium travel credit cards. These credit cards can save you hundreds -- if not thousands -- as long as you pay them off in full each month.

Credit cards are personal, and the best interest rate for you depends on your credit score and how you plan to use your credit card. Of course, lower is always better, so make sure you shop around before applying.

The Motley Fool owns and recommends MasterCard and Visa, and recommends American Express. We’re firm believers in the Golden Rule. If we wouldn’t recommend an offer to a close family member, we wouldn’t recommend it on The Ascent either. Our number one goal is helping people find the best offers to improve their finances. That is why editorial opinions are ours alone and have not been previously reviewed, approved, or endorsed by included advertisers. Editorial content from The Ascent is separate from The Motley Fool editorial content and is created by a different analyst team.