How it works
The calculator simulates your debt month by month: interest = balance × (annual rate ÷ 12); new balance = balance + interest − payment. It repeats until the balance reaches zero (the last payment is smaller). If your payment doesn't exceed the first month's interest, the debt can never be paid off and you'll see a warning. No new charges are assumed.
Worked examples
$5,000 at 18% paying $200/month
Paid off in 32 months (2 years 8 months), with $1,313.96 in total interest.
$12,000 at 22% paying $400/month
Paid off in 44 months (3 years 8 months), with $5,581.37 in total interest.