Credit Card Minimum Payment

How the Minimum-Payment Payoff Time Is Calculated

A credit card’s minimum payment isn’t a fixed dollar amount — it’s recalculated every statement, almost always as the greater of a small percentage of the current balance or a flat dollar floor. Because that required payment keeps shrinking right along with the balance, paying only the minimum every month can take decades and cost far more in interest than most people expect. This calculator simulates that month by month and contrasts it against a plain fixed payment, so the difference is concrete rather than abstract.

This is deliberately distinct from two related tools: Credit Card Payoff Calculator assumes you’ve already chosen a fixed monthly payment amount that never changes, and Debt Payoff Calculator compares payoff strategies across a whole list of debts. This calculator instead models the one mechanic neither of those does — a minimum payment that is itself a moving target.

The Formula

Every month, the issuer’s minimum payment is recalculated from whatever the balance happens to be that month:

$$\text{Minimum Payment} = \max\left(\vA{\text{Balance}} \times \vB{p} + \vC{\text{Interest}},\ \vD{f}\right)$$

where $\vB{p}$ is the minimum payment percentage (commonly 1–3%), $\vC{\text{Interest}}$ is that month’s accrued interest (some issuers fold this into the percentage part, some don’t — a checkbox above lets you match your own card), and $\vD{f}$ is the flat dollar floor (commonly $25–$35). Each month’s interest itself accrues the same way as any revolving balance:

$$\text{Interest} = \vA{\text{Balance}} \times \left(\text{APR} \div 12\right)$$

There’s no closed-form formula for “how many months does this take,” since the payment depends on the balance and the balance depends on the payment — so the minimum-only path is simulated directly, one statement month at a time, up to a 50-year cap.

Worked Example

A $5,000 balance at 20% APR, with a 2% minimum payment percentage (including that month’s interest) and a $25 flat floor:

• Paying only the shrinking minimum: paid off in 136 months (about 11.3 years), with $3,833.42 in total interest.
• Paying a fixed $366.67/month instead (twice the first month’s $183.33 minimum): paid off in just 16 months, with only $720.11 in total interest — 120 months sooner and over $3,100 less in interest, for a payment less than twice the original starting minimum.

Key Factors to Consider

• Even a modest fixed payment above the minimum dramatically shortens the payoff. As the worked example shows, a payment less than double the original minimum can cut the payoff time from over a decade to under two years — the leverage comes from paying down principal faster while it’s still relatively small, before interest has as much balance left to compound against.
• New charges added to the card reset the clock on this whole calculation. This calculator models a single existing balance with no new spending — continuing to use the card while carrying a balance adds new principal that also accrues interest, extending the real payoff time well beyond what this calculator shows for the starting balance alone.
• The minimum-payment trap is worse at a higher APR, all else equal. Since more of each shrinking minimum payment goes toward interest rather than principal at a higher rate, a higher-APR card takes even longer to pay off via minimum payments than a lower-APR card carrying the same starting balance.
• This calculator’s 50-year simulation cap reflects a real, if extreme, possibility. For a low starting minimum percentage combined with a high APR, the minimum-only path can genuinely take an extraordinarily long time — the cap exists so the simulation terminates, not because that outcome is unrealistic.

Common Mistakes

• Assuming the minimum payment amount stays the same every month. It doesn’t — it’s recalculated from the current balance every statement, which is exactly why “just paying the minimum” can stretch a payoff out for decades even though the dollar amount looks small and manageable month to month.
• Confusing this with a fixed-payment payoff calculation. If you already know the specific dollar amount you plan to pay every month, use Credit Card Payoff Calculator instead — this calculator is specifically for the “what if I only pay the minimum” scenario.
• Not checking the actual formula on a real statement. The percentage and dollar-floor defaults here are common, cited industry figures, not a universal constant — the exact numbers vary by issuer and sometimes by card product.

Useful to Know

Because the required minimum shrinks along with the balance, the very last stretch of a minimum-only payoff can drag on disproportionately long — a balance can spend years sitting at a few hundred dollars, with a minimum payment so small that nearly all of it still goes to interest rather than principal. This is also why issuer statements in the U.S. are legally required to show a “minimum payment warning” box disclosing roughly how long the payoff would take and the total interest cost at the minimum-only pace — a real-world version of exactly what this calculator computes, meant to make the tradeoff visible before it’s made.