How Payoff Time Is Calculated
Each month, interest is calculated on the remaining balance (balance times monthly rate). The monthly payment first covers interest; the remainder reduces principal. The calculator counts months until the balance reaches zero. If the monthly payment is less than or equal to monthly interest, the balance never decreases and "never" is shown.
The Extra Payment Field
Enter an additional monthly amount to see how much faster you could pay off the balance and how much interest you would save. Even $50 extra per month can save hundreds of dollars in interest on a high-APR card.
Frequently Asked Questions
With a fixed monthly payment greater than the monthly interest, the payoff time is: n = -log(1 - (r x balance)/payment) / log(1+r), where r is the monthly interest rate. If your payment equals or is less than the monthly interest, the balance will never decrease.
Minimum payments on credit cards are typically 1-3% of the balance or a fixed minimum (often $25-35), whichever is greater. Because most of each minimum payment goes toward interest, paying only the minimum on a large balance can take decades to pay off and cost several times the original balance in interest.
Even small increases in monthly payment significantly reduce payoff time and total interest because extra principal payments reduce the balance on which future interest is calculated. This calculator lets you compare two payment scenarios side by side.
According to the Federal Reserve, the average credit card interest rate in 2025 was approximately 21-22% APR for accounts assessed interest. Rates vary significantly by card type, issuer, and creditworthiness, ranging from 0% promotional rates to 30%+ for some store cards.
Two common strategies are the avalanche method (paying the highest-interest card first to minimize total interest) and the snowball method (paying the smallest balance first for psychological momentum). The debt payoff calculator on TheCalcHub compares both strategies.
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