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

Each month, interest accrues on the remaining balance, the payment covers that interest first, and the rest reduces principal. The last payment is capped at what is still owed. Total interest is the sum of the monthly charges, so a partial final payment is not counted as a full payment. Solving for a required payment from a target number of months uses the same formula algebraically, then rounds the payment up to cents to avoid leaving a balance due to rounding. If a proposed payment is at or below monthly interest, the balance cannot shrink. Fixed-payment schedules beyond 1,200 months are reported as unfinished; target dates are limited to 1,200 months.

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.

The formula this calculator uses

monthly interest = balance * APR / 100 / 12
actual payment   = min(planned payment, balance + monthly interest)
principal paid   = actual payment - monthly interest
balance          = balance - principal paid
total interest   = sum of the monthly interest charges
repeat until the balance reaches zero
if payment <= monthly interest the balance never falls
for a target n months: r = APR / 1200
required payment = balance * r / (1 - (1+r)^(-n))
at zero APR: required payment = balance / n
round the required payment up to cents, then cap the final payment

What it assumes without asking

• No further spending on the card
• A fixed payment every month and a fixed APR
• Interest applied once a month to the whole balance
• The final payment is capped at the remaining balance plus that month’s interest
• A fixed-payment schedule exceeding 1,200 months is reported as unfinished; the target-month input is limited to 1,200 months

One example, computed in full: $5,000 at 22.99%

What this calculator does not model

• Actual statement costs depend on daily balances, payment timing and issuer terms; this monthly model does not establish whether they will be higher or lower
• Promotional rates, balance transfer fees and deferred interest offers
• A minimum payment that falls as the balance falls, which is what makes real minimum-payment schedules longer than a fixed payment of the same size

The guide behind this tool

A number on its own does not tell you what to do with it. The first row is the one to look at: at this balance and rate, a payment barely below the monthly interest never clears anything. Credit utilization covers what the balance does to your score while you pay it down.

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.