How Revolving Credit Works
Revolving credit lets you carry a balance from month to month, paying only a minimum amount. A $1,000 purchase becomes a $25 monthly payment. Sounds manageable. But the remaining balance accrues interest at 15-25% APR. That is a rate most professional investors would celebrate as a return. Except here, it is working against you.
What Happens to a $1,000 Balance
At 20% APR with a $25 minimum payment: month 1, $1,000 balance accrues $16.67 interest. Your $25 payment reduces principal by only $8.33, leaving $991.67. Month 2: $991.67 accrues $16.53 interest. Principal drops by $8.47. At this pace, it takes about 66 months (5.5 years) to pay off $1,000, and you pay roughly $630 in total interest. A $1,000 purchase actually costs you $1,630.
The Debt Spiral
The real danger is adding new charges while carrying a balance. If you pay $25 per month but charge $50 in new purchases, your balance grows by $25 plus interest every month. The interest compounds on an ever-growing balance. This is the debt spiral that traps millions of people. A financial literacy book explains how to avoid and escape debt traps.
Make Compounding Your Ally, Not Your Enemy
Compound interest is a neutral mathematical force. When you invest, it multiplies your wealth. When you borrow at high rates, it multiplies your debt. At 5% annual return, $1,000 invested becomes $4,322 in 30 years. At 20% APR, $1,000 of revolving debt left unchecked would theoretically balloon to $237,000 (though credit limits prevent this extreme). The single most important financial rule for teenagers to learn: always put compounding on your side through investing, and never let it work against you through high-interest debt.