Credit card payoff calculator

Credit card interest compounds against a revolving balance, so the payment amount and the payoff timeline are two sides of the same equation - fix one and the other falls out of the math. Enter a balance and APR, then choose whether to see how long a fixed payment takes, or how large a payment needs to be to hit a target payoff month.

How the math works

The calculator runs the standard revolving-balance formula: each month, interest accrues on whatever balance remains, the payment covers that interest first, and whatever is left over reduces the principal. Solving for a payoff timeline from a fixed payment just runs that loop forward until the balance hits zero. Solving for a required payment from a target number of months runs the same formula backward, algebraically. Either way, the tool flags the one case that matters most: if a proposed payment is at or below that month’s interest charge, the balance cannot shrink, and the result shows a warning instead of a false payoff date.

Related reading

The math above only works because a payment above the interest line makes progress - the minimum payment trap and why paying only the minimum is a trap walk through why the minimum column on a statement is often close to that line. If you’re deciding how much extra to add, does a small amount extra toward principal really make a difference breaks down the effect in dollars, and what happens if you only ever pay the minimum covers the long-run cost in plain terms.

This tool is a general educational estimate, not financial advice or a payoff guarantee. Real card terms, fees, and promotional rates vary by issuer. See our disclaimer.