Today, I checked my credit card statement and found out that I have to pay $191.13 by October 10, 2019. The box at the bottom informed me that if I were to make the minimum payment ($10) at my current interest rate, then I would pay off my balance in 2 years and 0 months.

WTF?!??! At $10 per month, it would take me 24 months to pay off $191.13. So, I’d be paying $48.87 (= $240-$191.13) in interest over 2 years. The interest of $48.87 is 26% of the outstanding balance of $191.13. Ridiculous!

I also have to remember that if I make any other purchase during that two year period, then the amount owing would go up. that would mean that my bank would charge me even more interest.

So why isn’t credit card math taught in school?

I remember learning how to add, subtract, multiply, and divide. There were lessons on algorithms, on calculus, on algebra. My teachers spent time on the subject of simple interest, compound interest, and how they differed. I very definitely recall word problems involving distance and time.

Yet at no point during my many, many years of schooling do I remember any lessons on how to calculate credit card interest. Sure – I know that if I don’t pay my bill then I’ll be charged 19.97% annually. But is that compounded monthly or annually on my outstanding balance? Does that rate apply to any fees that I might have to pay if I miss a payment?

Math lessons would have been that much more useful to my adult life if I’d been required to solve the following math problem:

Henry indulged in some retail therapy and charged $7500 to his credit card. If he only pays back the minimum monthly payment of $225*** while being charged a rate of 29.99% annually, then how long will it take Henry to repay his credit card? Secondly, how much interest will Henry pay on that credit card debt? *** The minimum monthly payment is equivalent to 3% of the outstanding balance.

Not My Parents’ Fault

I’m not going to blame my parents for this gap in my education. I’m fairly certain that credit cards weren’t a thing when they were in school. You can’t teach what you don’t know.

Credit card math was never an issue in my house when I was growing up. My parents had two credit cards between them. My dad had a gas card that he used when we took our annual summer holiday. My mom had a retail store card that was used to buy appliances for the house. What they taught me about credit cards is as follows: NEVER CARRY A BALANCE.

Full stop. This is what I learned from my parents’ example respecting the issue of credit cards. This is a basic lesson that pretty much works in all situations involving a credit card balance. Pay your credit card balance in full every single month.

Unfortunately, my parents’ example failed to explain how credit card interest will be calculated for those unfortunate folks who do not pay their balances in full each and every single month. Though incredibly useful and entirely admirable, the lesson from my parents taught me nothing about credit card math.

Surely the Credit Card Websites Have the Answers I Need

Let’s recap. My parents didn’t teach me credit card math at home. My schools didn’t teach me credit card math even though I was in their care and custody from the ages of 6 to 17. Despite receiving my undergraduate degree from the school of business, I never learned how credit card interest was calculated. For that matter, my business degree was also useless in teaching me about the nefarious death-grip of student loans or anything else related to personal finance.

The next logical place to search for answers is from the source. Surely the banks who issue credit cards would have a calculator dedicated to credit card math on their website. It would seem only logical that they would have some kind of online tool that explicitly shows how interest on credit cards is calculated and compounded. Customers would be able to enter their outstanding balance and the interest rate on the card then press a button to get a number representing how much interest would be owing on the outstanding debt.

CIBC offers a credit card calculator to encourage you to accumulate points. There’s not a single mention of how the interest is calculated if you don’t pay your bill in full. To be fair, the inquiry “How is interest calculated on my purchases?” results in a link to the cardholder agreement. Pages 6-7 of CIBC’s cardholder agreement set out how payments are applied to a credit card balance. Yet, there’s no calculator that allows borrowers to plug in their own numbers to see just how much interest they will pay if they don’t pay their balance in full.

I’m not picking on CIBC. I went to Scotiabank’s website too, and they didn’t have a credit card interest calculator either. Similarly, TD’s website was a bust. BMO has a variety of calculators for mortgages and savings, but does not offer any online calculators to help their customers figure out how interest is calculated on credit cards.

Maybe Canada’s biggest bank has what I want… RBC’s website isn’t perfect but atleast it offers an explanation, but not a calculator, of how interest is charged on its credit cards. Kudos to RBC for not making its customers wade through a cardholder agreement!

How disappointing… It’s almost as though the purveyors of credit cards do not want their customers to be able to figure out how much interest they will have to pay on their credit card debt if balances aren’t paid in full. I’m willing to go out on a limb here. I believe that credit card issuers don’t want their customers to understand credit card math.

Even the Gurus Can’t Answer my Questions!

If you’re not yet familiar with his teachings, then allow me to indulge for a moment. Dave Ramsey has created a series of Baby Steps to help regular people get out of debt and to achieve wealth. To be clear, I love the lessons about how to get out of debt by creating a debt snowball. If you’re ready to commit to a get-out-of-debt-plan, then start doing what Dave Ramsey says and keep doing it until all of your debt is gone.

Yet, even Dave Ramsey fails to explain how credit card interest is calculated. This is hardly surprising. He hates debt and he encourages people to never carry credit cards. Still, he’s been in the business of helping get out of debt for nearly 3 decades. I thought that maybe, just maybe, he would be the one to explain credit card math to folks…even if just to tell people that they’re stupid for partaking of it.

Government of Canada to the Rescue!

The good folks at the Financial Consumer Agency of Canada have a partial solution. Their website offers a credit card payment calculator that will tell you how much interest will be charged if you don’t pay your credit card off in full. The calculator lets you add in your current balance and your interest rate. The search results ably demonstrate the impact of paying more than the minimum monthly balance and how much interest can be saved.

So far, this is the best credit card math tool that I’ve found online.

I’m still in the dark about how to calculate interest on my credit card balance. So I will resort to my parents’ wisdom. I resolve to never carry a balance. The mystery of credit card math may or may not haunt me for the rest of my days, and that might be okay.

So long as I pay off my credit card balance every single month, I’ll never need to worry about the box at the bottom of my statement which tells me that it will take 24 months of my life to pay off an amount as small as $191.13 if I make the minimum monthly payment while never charging anything else during that time period.