Credit Card Payoff Calculator

The credit card payoff calculator shows how long it will take to clear your balance and what it costs you in interest. It runs four scenarios side by side: your payment, your payment plus $50, your payment plus $100, and the minimum payment. The gap between the first and the last is usually the most expensive number on the page.

Key formulas:

Minimum Payment Payoff (geometric series): n = −log(1 − (r × B) ÷ P) ÷ log(1 + r) where n = months, r = monthly rate (APR ÷ 12), B = balance, P = payment amount.

Monthly Interest Charge: Interest = Current Balance × (APR ÷ 12)

Fixed Payment to Pay Off in n Months: P = B × r × (1+r)^n ÷ ((1+r)^n − 1)

Total Interest Paid = (Monthly Payment × Number of Payments) − Original Balance

What each variable means:

• Balance (B): current amount owed on the card.
• APR (Annual Percentage Rate): typically 19.99% to 29.99% on U.S. credit cards.
• Monthly Rate (r): APR ÷ 12, so a 24% APR is 2% per month.
• Minimum Payment: usually 1% of the balance plus interest, or a flat 2% of the balance, with a floor around $25. It is the most expensive way to clear a card, by a wide margin.

Worked example: Balance: $5,000. APR: 24%, so 2% a month.

Fixed $200/month scenario: n = −log(1 − (0.02 × 5,000) ÷ 200) ÷ log(1.02) = −log(0.5) ÷ log(1.02) = 35.0 months

Round that up: the 36th payment finishes it. But the closed form gives a fractional month for a reason, and the last payment is only $0.56, not another $200. Multiplying $200 × 36 overstates the interest by $199, which is the mistake almost every payoff table makes. The calculator above amortises month by month instead, so it reports $7,000.56 paid and $2,000.56 in interest.

Minimum payment scenario, and why it is worse than you have been told:

A typical US minimum is 1% of the balance plus that month’s interest, floored at $25. On this balance that starts at $150 and shrinks every month as the balance falls, which is the trap: the payment chases the debt down instead of chasing it out.

Result: 234 months, or 19.5 years, and $8,887 in interest on a $5,000 debt. You repay nearly three times what you borrowed.

Paying $200 instead of the minimum saves $6,886 in interest and 16.5 years.

A warning about the other common minimum rule. Some cards set the minimum at a flat 2% of the balance with no separate interest component. At a 24% APR the monthly interest is also 2%, so the payment exactly cancels the interest and the balance never moves until the $25 floor eventually takes over. That card is mathematically a permanent debt. Check which rule yours uses; it is in the cardholder agreement, not on the statement.