Your Minimum Payment Formula, Demystified
Here is a myth worth burying: that the minimum payment is what keeps you safe, sitting comfortably in your account while the debt shrinks a little every month. In reality, the minimum is engineered to keep the account open and current — not to pay it down. At the start of a balance, the minimum covers mostly interest, and the part that actually touches principal is comically small. Once you see the formula, you will never mistake "current" for "progress" again.
The Formula on Your Statement
Most issuers calculate the minimum as max(1%–3% of the balance, $25) — the most common being 2% of the balance or $25, whichever is larger. So a $5,000 balance has a minimum of around $100. A $900 balance has a minimum of $25 (since 2% of $900 is only $18, which the $25 floor overrides). That floor exists so payments never become trivially small. But here is the uncomfortable part: nearly all of that early payment is interest.
Walk through the $5,000 card at 22% APR. At a 2% minimum, the payment starts near $100. Monthly interest at 22%/12 (about 1.83%) on $5,000 is roughly $92. Of your $100 minimum, about $92 buys interest and only $8 reduces the balance. You mailed in a hundred dollars and the debt shrank by the price of a lunch. And because the minimum is a percentage of the falling balance, it shrinks right along with the debt — so the payoff stretches toward decades, and total interest can exceed double the original balance.
What That Means For You
Paying only the minimum is, in effect, renting your balance at a punishing rate. The escape is to stop matching the minimum and instead fix a dollar amount you will not let fall. The payoff formula makes the difference vivid:
n = -log(1 − i·B/P) / log(1 + i)
At $200 a month on $5,000 at 22%, you finish in about 34 months with roughly $1,750 in interest. At $350 a month, it is about 17 months with roughly $850 in interest. Same debt, same rate — the minimum's percentage-based decline is exactly what converts "I'm paying on time" into "I've been paying them for years."
Beating the Minimum
Set your auto-pay to a fixed figure, not a percentage. Roll every free dollar in as your balance drops. And never let the floor trick you into gratitude: the $25 minimum on a small balance is a permission slip for the bank to keep accruing interest on the rest. Pay the number that ends the debt, and the formula stops working against you.
Frequently Asked Questions
How exactly do issuers calculate my minimum?
Usually max(1%–3% of the balance, $25), most commonly 2% or $25, whichever is larger. The percentage and floor vary by issuer, so your statement is the source of truth.
Does paying the minimum hurt my credit?
No, as long as you pay it on time — the minimum is what keeps your account current and your score intact. The cost is financial, not credit: it barely reduces the balance and lets interest compound for years.
What is the right percentage to pay instead?
A fixed dollar amount beats any percentage. On a $5,000 balance at 22%, $200 a month (~4%) clears in about 34 months, while the 2% minimum stretches the term dramatically. The longer the payment, the more interest you pay.
Can my minimum payment increase?
Yes. It rises as your balance grows, under a penalty APR, or when your issuer revaluates your account. A higher rate also makes the interest portion of the minimum larger, freezing the balance even longer.