Effortless Math › Personal Finance › What Paying the Minimum on a Credit Card Actually Costs
What Paying the Minimum on a Credit Card Actually Costs
Most explanations of credit card interest use a flat 2% minimum payment, which is not a universal issuer rule and produces an answer that is wrong by decades. This page uses one common issuer rule, builds the schedule month by month, and lands on a number worth remembering.
From APR to a monthly finance charge
A card quotes an annual percentage rate but charges you every month. Divide by twelve to get the monthly periodic rate, then apply it to the balance.
Worked example
A balance of $3,000.00 on a card at 22.99% APR.
Most issuers actually charge on the average daily balance, which accounts for when in the cycle you charged and paid. The monthly rate method above is a simplified estimate and a useful model for learning what is happening.
What the minimum payment really is
Textbooks use 2% of the balance. Card agreements vary. For this example, use this common issuer rule. Check your own card agreement:
The distinction matters enormously. A flat 2% of a shrinking balance never finishes paying the card off, because the payment shrinks as fast as the balance does. Interest plus 1% does finish — eventually.
The first payment
On the same $3,000.00 at 22.99%:
Two-thirds of the first payment is rent on the money
The first minimum payment is $87.48. $57.48 of it is interest. The balance falls by $30.00 — about 34% of what you paid. That ratio improves, but slowly.
Four months of a real payoff
Every month: interest is added, the payment comes off, and what is left carries forward.
| Starting balance | Interest | Minimum payment | Goes to principal | New balance |
|---|---|---|---|---|
| $3,000.00 | $57.48 | $87.48 | $30.00 | $2,970.00 |
| $2,970.00 | $56.90 | $86.60 | $29.70 | $2,940.30 |
| $2,940.30 | $56.33 | $85.73 | $29.40 | $2,910.90 |
| $2,910.90 | $55.77 | $84.88 | $29.11 | $2,881.79 |
After four payments totalling $344.69, the balance has fallen from $3,000.00 to $2,881.79.
The number at the end
Paying the minimum, to the finish
$3,000.00 at 22.99% APR, paying exactly the minimum every month and charging nothing new.
Twelve years and four months to clear a balance that could be run up in an afternoon. That is the number worth carrying around.
Three ways to pay the same balance
| Approach | Monthly payment | Months | Total interest | Total paid |
|---|---|---|---|---|
| Minimum only | $87.48 falling | 148 | $4,221.25 | $7,221.25 |
| Fixed $150 | $150.00 | 26 | $819.36 | $3,819.36 |
| Fixed $300 | $300.00 | 12 | $362.60 | $3,362.60 |
Holding the payment at a flat $150.00 — roughly what the minimum starts at anyway — cuts the interest from $4,221.25 to $819.36 and the term from 148 months to 26. The whole trick is that the payment stops shrinking.
The grace period, and how you lose it
If you pay the full statement balance by the due date, most cards charge no interest on purchases at all. That window is the grace period, usually 21 to 25 days after the statement closes. Used properly, a credit card is an interest-free short-term loan.
Two things end it:
- Carrying a balance. Once you pay less than the full statement balance, most issuers suspend the grace period. New purchases then start accruing interest from the day you make them, and the grace period does not come back until you clear the balance in full and stay clear for a cycle.
- Cash advances. These never have a grace period. Interest starts immediately, the APR is usually higher than the purchase APR, and there is a fee of around 3% to 5% on top.
Practice, with answers
1. A card has an APR of 19.99%. What is the monthly periodic rate, and what is the finance charge on a $1,200 balance?
Answer: Monthly rate about 1.666%; finance charge $19.99.
2. On that same $1,200 balance at 19.99%, what is the minimum payment, and how much of it reduces the balance?
Answer: Minimum $35.00, of which $15.01 reduces the balance.
3. Sofia charges $1,400 on a card with a 25-day grace period and pays the entire statement balance by the due date. What interest does she pay? What if she pays $1,300 instead?
Answer: Nothing if she pays in full. Paying $100 short costs her far more than $100 of interest, because it also ends the grace period on everything she buys next month.
4. A $3,000 balance at 22.99% is paid at a fixed $150 a month instead of the minimum. How much interest is saved?
Answer: $3,401.89 saved, and the card is clear 122 months sooner.
Check what you learned
Take the 10-question credit and debt quiz. It opens on the hub, and you will see your score, the correct answers, and explanations when you finish.
Keep going
- Compound interest, worked out — the same formula, running in your favor for once
- The 50/30/20 budget — where the fixed payment has to come from
- The Rule of 72 — why 24% means the balance doubles every three years
Questions people ask
How long does it take to pay off $3,000 with minimum payments?
At a 22.99% APR and the standard minimum of interest plus 1% of the balance with a $35 floor, about 148 months — 12 years and 4 months — and roughly $4,221.25 in interest. The interest alone is more than the original balance.
What is the actual minimum payment formula?
Most US issuers charge the greater of a flat floor, commonly $25 to $35, or the current month's interest plus about 1% of the balance. Some use a flat percentage of the balance between 2% and 3% with the same floor. The exact rule is in the cardholder agreement under Minimum Payment.
Why is paying the minimum so expensive?
Because the payment shrinks as the balance does, so the portion actually reducing the debt stays small for years. On the first $87.48 payment of a $3,000.00 balance, $57.48 is interest and only $30.00 touches the principal. Holding the payment flat instead of letting it fall is what breaks the cycle.
Does paying the full statement balance avoid interest?
On purchases, yes, at almost every card. Pay the full statement balance by the due date and the grace period means no interest is charged. Carry any balance and most issuers suspend the grace period, so new purchases start accruing interest immediately until you clear it and stay clear.
Do cash advances have a grace period?
No. Interest on a cash advance starts the day you take it, the APR is usually higher than the purchase APR, and there is a fee of roughly 3% to 5% on top. A cash advance is the most expensive routine way to use a credit card.
Part of the Personal Finance hub — ten units, a free pacing guide, and worked examples with answers.