How this calculator works
The calculator models a fixed APR and applies interest monthly to the remaining balance. It compares your current planned monthly payment with the same payment plus any extra amount you choose.
A one-off payment is applied at the start of the accelerated scenario. No new card spending is assumed.
How to use it
- Enter the current card balance and purchase APR.
- Enter the amount you genuinely expect to pay each month.
- Add an optional one-off payment and regular extra payment.
- Compare the payoff date and total interest with and without the extra payments.
- Try several payment levels to find a target that is ambitious but sustainable.
Assumptions and limitations
This is a simplified payoff model. Credit-card minimum-payment formulas, promotional rates, fees, cash advances and rate changes vary by provider. If you continue spending on the card, the real payoff time will be longer.