The Cost of Credit Cards

Data from the Federal Reserve show that Americans owe close to 1,000 billion dollars of revolving debt* (which I’ll refer to as credit-card debt).

Dividing the total credit-card debt ($1,000,000,000,000) by the adult population of the United States (the 245 million (245,000,000) persons over age 18) shows us that, on average, every American adult carries a total balance of about $4,000 on his or her credit cards.

Note that this is an average for all adults.  Because we know that some adults have no credit-card debt, we can be certain that the average total credit card balance of adults that do carry credit-card debt must be higher than $4,000.  Many of them carry these balances for months, or years, or decades.

How much does it cost to carry a credit-card balance?

The answer depends on two things:

  • the size of the balance
  • the credit card’s interest rate

Let’s assume Joe College gets his first credit card.  A short time later he has spent $1,000 — all charged on the card.  Thereafter, the credit-card balance doesn’t go much higher (let’s say that’s close to the card’s credit limit, and Joe’s a smart guy; he knows he’ll be hit with a penalty fee if he goes over the limit and it will be bad for his credit score).  If Joe paid off the entire $1,000 as soon as he got the bill, then there’d be no balance and therefore no interest charge.  But that’s not what happens.  Joe makes payments in an attempt to pay it off, but too-often he gives in to temptation and uses the card to buy something he wants, or there’s something he urgently needs and he charges it.  Thus, the balance is sometimes a little below $1,000, sometimes a little above $1,000, but it averages $1,000 for an entire year.

Most credit cards have interest rates between 10% and 30% per year.  People with good credit scores (who are probably likely to have low balances) might get cards with rates that are lower, while those with bad credit scores might have cards with interest rates that are even higher. So let’s assume the interest rate on Joe’s card is 15%.

The average balance on Joe’s card is $1,000 and he pays 15% interest per year.  How much does that cost him?

The annual amount of interest paid is a simple calculation of the interest rate as a percentage of the average balance, or:

[interest rate] / 100 × [$ average balance] = amount of interest paid per year

which in our case is:

15 / 100 × $1,000 = $150

or:

0.15 × $1,000 = $150 **

The $150 is broken down into monthly changes of $12.50 that are added to each month’s bill. If Joe pays only $12.50 per month, the $1,000 balance would never be reduced.  If he doesn’t even pay the $12.50 interest change each month, the credit-card balance grows as the interest gets compounded.  His debt would also grow because he’d be hit with a late fee that would almost certainly be more than the interest for one month.  A payment greater than $12.50 reduces the balance by whatever amount is additional to the interest.

We assume that Joe makes the payments that are normally required, which takes care of each month’s interest charge and applies some additional amount to the balance — but, as already noted, Joe keeps making purchases with his credit card, so the average balance is continually around $1,000.

This costs him $150 per year.  Consider that for a moment.  After 7 years, Joe will pay more than $1,000 in interest, effectively doubling the cost of the first $1,000 worth of purchases he made soon after he got the card.  If he keeps going he will pay for those purchases several times.  After another 7 years, the credit-card issuer will have another $1,000 of Joe’s money, … and so on for as long as Joe carries that balance on his credit card.

If Joe ever pays late or misses a payment on this credit card or any other debt, it’s very likely, nearly a certainty really, that the credit-card issuer will increase the interest rate on Joe’s card.  In fact, the interest rates might go up on all of Joe’s credit cards.

If the rate goes up to 20%, Joe will pay $1,000 every 5 years.  At 30%, he will pay $1,000 in interest charges every 3 and 1/2 years.

Let’s remember that Joe’s spending spree stopped when he reached the card’s credit limit.  After that — after he charged that first $1,000 — he was able to keep new charges on his credit card and the amount he was able to pay each month in equilibrium.  It’s that initial $1,000 that made Joe a permanent borrower.

If he had been able to find that equilibrium when the credit-card balance was $0, and kept his average balance at zero by charging only what he could afford to pay off each month, he would have saved that $150 each year.

The Bible says that the borrower is slave to the lender: “The rich rule over the poor, and the borrower is slave to the lender.” — Proverbs 22:7.  That should make us wonder:  What was it, in that first $1,000 of charges, that was so important, so essential, that Joe had to have it, even at the cost of turning himself into a slave?  After he’s paid over $1,000 in interest, can Joe even remember what he’s paying for as he finishes paying for it for the first time and begins paying for it the second (or third …) time?  As the old saying goes, the purchase should outlast the payments.  If Joe can’t even remember what it is he’s paying interest on, can it be important enough to pay for it over and over again?

Think how much better off he would be if he had resisted the temptation to over-use his credit card.  If he had

  • cooked dinner at home instead of going out to a restaurant,
  • eaten DIY oatmeal instead of buying a fast-food breakfast,
  • invited friends to play cards or a board game, or just watch TV, instead of going to a movie, concert, or sporting event,
  • had friends over to his house to drink a few beers instead of going to a bar or club,
  • shopped for new (to him) clothes at Goodwill or similar thrift store,
  • gotten free or nearly-free furniture, television, stereo, etc., from Craigslist or hand-me-downs from friends or family.

Had he done those thing, he would have been at least $1,000 richer every 7 years.

Now consider that the average American has a credit-card balance of over $4,000.  Take a look at Joe’s story again, but multiply every number by 4.  A balance of $4,000 at 15% costs $4,000 in interest payments every 7 years.  At 20%, it’s $4,000 every 5 years.  At 30%, $4,000 every 3 and 1/2 years — over $1,000 per year!

Look at yourself: Are you an average American?  Are you running a credit-card-interest tab (put it on the card, put it on the tab) that’s costing you hundreds, or thousands, of dollars each year?

Remember the annual-spending tip.  If you earn, say, $50,000 per year and you’re paying $500 in credit-card interest, then interest on credit-card debt is costing you a full 1% of your income.

Are you paying 1% of your income in interest payments to the banks when at the same time you’re saving and investing less than 10% of your income for your own future … and maybe telling yourself you can’t save 10%, there’s nothing you can cut down on.  Well, here’s an idea:  how about cutting down on the credit-card interest you pay?  Instead of paying interest charges to make other people (the people that own stock in banks, like me!) richer, you could be investing that money and earning interest and dividends for yourself.

The moral of the story should be clear.  If you don’t have a credit-card balance, do everything you can to avoid getting one.  If you have one, do everything you can to pay it off.


* Revolving debt is basically what people owe on bank-issued credit cards and retailer-issued store and gas cards, which allow the borrower to make additional charges without any additional application process. Thus, many borrowers add new debt as fast as they pay off old debt. Home equity line of credit (HELOC) loans would also seem to fall into this category, but the Federal Reserve does not include loans secured by real estate in total revolving debt.

** The actual calculation used by credit card issuers is a bit more complex.  It involves dividing the interest rate by the number of days in a year (~365) and multiplying that by the average daily balance each month.  But our approximation works well enough for our purposes.

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